by Marc A. Pugliese
[for more articles on this subject see www.keepthefilioque.com ]
The point of the filioque is that the Son is also the source of the Holy Spirit along with the Father. The Holy Spirit receives the divine essence not only from the Father, but also from the Son. In the West it has been proper to make the distinction that the Holy Spirit comes from the Father alone with respect to absolute, unoriginate, unbegotten cause, because only the Father is unbegotten and unoriginate, in which case one can say that the Holy Spirit proceeds from the Father through (διά) the Son. However, in the West it is said that one must at the same time say that the Holy Spirit proceeds from the Son also, as from a mediate, originated, begotten cause, and that the Son communicates the divine essence to the Spirit in exactly the same way as the Father.
Reasons Why the Filioque Should Be Maintained
1. The Eastern Churches contention that the idea of the Holy Spirit also proceeding from the Son, in the sense intended by the filioque, did not develop in the Church until much later is not true.
Photius and others claim that none of the Church Fathers nor any council has said that the Holy Spirit proceeds from the Son. As any survey of church history will show, the concept of the “unanimous consent of the fathers” is a chimerical ideal that does not exist in reality. In fact, there are plenty of witnesses, in the Greek as well as Latin Church Fathers, who say what the filioque affirms. Among the Greek Fathers, Athanasius (d. 373), the great defender of Trinitarian and Christological orthodoxy, said that the Spirit originates παρὰ τοῦ λόγου, and compared how the Spirit receives His deity from the Son to how the Son receives His deity from the Father. Likewise defenders of Trinitarian orthodoxy, the Cappadocian Fathers bear witness to the Holy Spirit deriving His being from both the Father and the Son. In defending the Holy Spirit’s consubstantiality with the Father and Son, Basil expressly said that the Holy Spirit “has His being” from the Son. Gregory Nazianzus similarly linked the Holy Spirit’s being with the being of the Son. Epiphianus (367–403) referred to the Holy Spirit as proceeding from the Father and “receiving” from the Son. He also said that the Spirit “has his consubstantial being” from the Father and the Son, and referred to the Holy Spirit as “the bond of the Trinity” similar to the way Augustine would later see the Holy Spirit as the bond of love between the Father and the Son. Cyril of Alexandria (d. 444) said that the Spirit is proper to the Son, He proceeds from the Son, and that He proceeds from the Father and the Son. Maximus the Confessor (d. 662) said that the Holy Spirit is διὰ μέσου τοῦ λόγου, “by means of the Word.” Gregory of Palamas (d. 1359) attested that the Spirit is the bond of love between the Father and the Son, much in the way Augustine did.
As for the West, in the 200s Tertullian, combating Sabellian modalism in Against Praxeas, compared the Spirit to the fruit of a tree, the Father being the tree’s roots and the tree being the Son. Using similar analogies, he says the Holy Spirit is “third from God and the Son.” Hilary of Poitiers (d. 367) explicitly said that the Holy Spirit proceeds from the Father and the Son. In 381 Ambrose of Milan also expressly said that the Spirit proceeds from the Father and the Son,and referred to the Son, along with the Father, as the “fount” of the Spirit. In 382 a local synod in Rome interpreted the sending of the Holy Spirit by both the Father and the Son in the economy of salvation, as testified to in Scripture, as reference to the origin of the Holy Spirit. Augustine’s teaching on the Holy Spirit proceeding from both the Father and the Son is, of course, well-known.
Leo the Great, who was the bishop of Rome during the Council of Chalcedon, clearly said in 447 that the Holy Spirit proceeds from the Father and the Son, and stated explicitly that this procession is that the Holy Spirit receives His divine essence from the Father and the Son. In 447, the Second Council of Toledo, directly addressing Visigothic Arianism, plainly said that the Holy Spirit proceeds from both the Father and the Son, which of course means that the Son is as fully divine as the Father. In the following centuries further councils in Toledo said the same, and Gregory the Great, bishop of Rome from 594–600, clearly said that the Holy Spirit proceeds essentially from the Son.
Now while in their contexts these various statements of the Church Fathers often were said in making a point other than that the Holy Spirit proceeds from the Son also, they nonetheless stated that the Spirit receives His divinity from the Son just as much as He does from the Father. In fact, many of the statements about the double procession of the Holy Spirit from the Father and the Son were made in defense of Christ’s full divinity and consubstantiality with the Father; the Son is so much God as the Father that the Son likewise spirates the Spirit along with the Father, putting the Spirit in possession of the divinity just as the Father does.
These testimonies from the Church Fathers, to which many more could be added, serve both to (1) prove that there is no paucity of testimony to the Holy Spirit’s procession from the Father and the Son among the Church Fathers and early councils, and (2) show that the intention behind the filioque was a part of Christian theology practically from its incipience and was not a novelty imported into theology at the time that the filioque clause became an official part of the creed.
2. The Reformed Confessions have consistently affirmed the Double Procession, or the filioque, with the same intention as the Western Church as a whole.
Again with the caveat that creeds or confessions are fallible and that, while sources for theology, they hold a far second place with the Word of God in Scripture, it is significant that almost every great Reformed confession that deals at length with the Trinity contains the Double Procession. These include the French Confession of Faith (1559), the Belgic Confession (1561, revised 1619), the Second Helvetic Confession (1566), and the Westminster Confession of Faith (1647).
3. The Holy Spirit is the Spirit of Christ
Calvin proves the filioque using Scripture by appealing to the passages that speak of the Holy Spirit as also the “Spirit of Christ” or the “Spirit of the Son”:
For this reason, the Son is said to come forth from the Father alone; the Spirit, from the Father and the Son, at the same time. This appears in many passages, but nowhere more clearly than in chapter 8 of Romans, where the same Spirit is indifferently called sometimes the Spirit of Christ [v. 9], sometimes the Spirit of him ‘who raised up Christ . . . from the dead’ [v. 11]—and not without justification. For Peter also testifies that it was by the Spirit of Christ that the prophets prophesied [2 Pet 1:21; cf. 1 Pet 1:11], even though Scripture often teaches it was the Spirit of God the Father.
Similarly, later the Westminster Confession uses Gal 4:6, “Because you are sons, God sent the Spirit of His Son into our hearts, crying ‘Abba, Father,’” to prove that the Holy Spirit proceeds from the Son as well as from the Father. Photius, of course, had already dealt with Gal 4:6 and the “spirit of Christ” passages by making the distinction between being “of” and “proceeding from”; the Scriptures say the former, which is quite unqualified and thus ambiguous in itself, but never say the latter.
4. Although the filioque is not taught explicitly and expressly in Holy Scripture, it is taught implicitly and virtually, just as the Doctrine of the Trinity as a whole is only taught implicitly and virtually, not explicitly and expressly.
As just mentioned above, the Holy Spirit is sometimes called the “Spirit of the Son” and the “Spirit of Christ,” and not just the “Spirit of the Father” (Rom 8:9; Gal 4:6; Phil 1:19; 1 Pet 1:11). The “Spirit of His Son in our hearts, crying, Abba, Father” (Gal 4:6) tightly ties the Son and the Spirit together. The Holy Spirit in us is the Spirit that relates to God as a beloved Father. The Spirit in us has filial characteristics. He is called the Spirit of His Son. There seems more to the relationship between the Son and the Holy Spirit than a mutual procession from the Father. Is this Spirit ever encountered apart from the Word, the Second Person of the Trinity? An ancillary deductive proof is that if God is Spirit (John 4:24) and if the Son is fully God (John 1:1; 5:18; 8:58), then the Son must be Spirit, as 2 Cor 3:17–18 expressly says, and whence proceeds the Third Person of the Trinity. How can it not be, then, that the Holy Spirit does not proceed from the Son as well as from the Father? The fact that the Spirit is fully the Spirit of the Son as much as the Spirit of the Father shows how the Trinity is a tight unity. In defending the Double Procession, Francis Turretin says on John 16:13–15:
Whatever the Spirit has, he has from the Son no less than from the Father (John 16:13–15), and as the Son is said to be from the Father because he does not speak of himself, but of the Father (from whom he receives all things), so the Spirit ought to be said to be and to proceed from the Son because he hears and speaks from him.
Based on the statements regarding the Son in relationship to the Father in the Gospel of John, Turretin concludes that the Holy Spirit must proceed from the Son in the same way as He proceeds from the Father, by logical inference, or as the Westminster Confession says, “by good and necessary consequence.” He writes: “It is implied because the mission of the Spirit is ascribed to him and whatever the Father has, the Son is said to have equally (John 16:15).”
Turretin’s point is also buttressed from John 5:18–32, where Jesus explains how many of the Father’s attributes (giving life, judging, receiving glory and honor, and resurrecting) are the Son’s as well. Jesus clearly says here that “whatever the Father does, these things also the Son likewise does” (John 5:19b). Upon such revelation is the venerable Trinitarian axiom, In Deo omnia sunt unum, ubi non obviat relationis oppositio. That is, the Father and the Son share everything in common, except for their relations of origin; the Father begets and the Son is begotten. These opposing relations of origin are the only things that they do not share. Thus they both participate in the procession of the Holy Spirit, which is the relation of opposition distinguishing the Holy Spirit from the Father and the Holy Spirit from the Son. Theologically, it is argued that if the axiom is correct, then the Holy Spirit must proceed from the Son as well as from the Father, or else there would be no opposing relation of origin between the Son and the Spirit, and thus no distinction between the Son and the Spirit. Actually, Yves Congar explains that Photius’s condemnations were based on the supposition that properties differentiate the divine persons instead of solely the genetic relations of opposition.
It must be readily admitted that the Scripture never openly and overtly discusses the eternal relationship between the Holy Spirit and the Son in the ontological or immanent Trinity. However, much the same can be said about eternal relationship between the Father and the Son, most of which is known from the relationship between the Father and the Son in the economic Trinity, or from the relationship between the Son and the Father in salvation history. It is to the economic Trinity that we now turn.
5. The economic Trinity, including the missions of the persons of the Trinity, corresponds to the immanent or ontological Trinity.
John 15:26 says that the Spirit of Truth “proceeds” or “goes out from” the Father (ἐκπορεύεται), yet this by no means constitutes a denial that He also proceeds or goes out from the Son. John 14:26 says that the Father will send the Holy Spirit without mentioning the Son, but this does not imply that the Son will not send the Holy Spirit, since, in fact, John 16:7 says that the Son will send the Holy Spirit.
In fact, in the same sentence in John 15:26 where He says that the Holy Spirit proceeds or goes out from the Father, Jesus also says that He will send the Holy Spirit from the Father. In this way, Photius’s “mystical teaching” in John 15:26 about the procession of the Holy Spirit from the Father by no means constitutes a teaching that the Holy Spirit does not proceed from the Son.
The Scriptures do clearly say, however, that the Son will send, or has sent, the Holy Spirit (John 1:33b; 15:26; 16:7; Acts 2:33). Many see here a reflection of the eternal relationship between the Son and the Holy Spirit:
And if the Son together with the Father sends the Spirit into the world, by analogy it would seem appropriate to say that this reflects eternal ordering of their relationships. This is not something that we can clearly insist on based on any specific verse (much like the Doctrine of the Trinity in general), but much of our understanding of the eternal relationships among the Father, Son, and Holy Spirit comes by analogy from what Scripture tells us about the way they relate to the creation in time. It is natural to suppose that the double sending of the Spirit reflects, and so reveals, a double procession in the divine life-pattern, but Scripture speaks only of the former, leaving the latter totally opaque to us in fact, however much it is argued over.
Since the beginnings of Christian theology, theologians have seen revelations of intratrinitarian life in the Gospel of John, especially between the Father and the Son. Examples include: “For as the Father has life in himself, so he has granted the Son to have life in himself” (John 5:26); “I tell you the truth, the Son can do nothing by himself, he can do only what he sees his Father doing, because whatever the Father does the Son also does” (John 5:19); “If God were your Father, you would love me, for I came from God and now am here. I have not come on my own; but he sent me” (John 8:42);”. . . no one can snatch them out of my hand . . . no one can snatch them out of my Father’s hand. I and the Father are one” (John 10:28b; 29b–30); “Father, I thank you that you have heard me. I knew that you always hear me, but I said this for the benefit of the people standing here, that they may believe that you sent me” (John 11:41); and “Philip said, ‘Lord, show us the Father and that will be enough for us.’ Jesus answered, ‘Don’t you know me, Philip, even after I have been among you such a long time? Anyone who has seen me has seen the Father. How can you say, “Show us the Father”? Don’t you believe that I am in the Father and that the Father is in me?’” (John 14:8–10a). It would also seem that the references to sending and missions in the Gospel of John, too, reveal a deeper reality about the intratrinitarian life.
In fact, Karl Rahner’s famous trinitarian axiom that “the economic Trinity is the immanent Trinity, and the immanent Trinity is the economic Trinity” is predicated on the fact that if God truly reveals himself in the economy of salvation, that is, in how the persons of the economic Trinity work, then the economic Trinity must reveal something about the inner, immanent, intratrinitarian divine life:
If we admit that every divine person might assume a hypostatic union with a created reality, then the fact of the incarnation of the Logos ‘reveals’ properly nothing about the Logos himself, that is, about his own relative specific features within the divinity. For in this even the incarnation means for us practically only the experience that God in general is a person, something which we already knew. It does not mean that in the Trinity there is a very special differentiation of persons. . . . we cling to the truth that the Logos is really as he appears in revelation, that he is the one who reveals to us (not merely one of those who might have revealed to us) the triune God, on account of the personal being which belongs exclusively to him, the Father’s Logos. . . . what Jesus is and does as man reveals the Logos himself . . . here the Logos with God and the Logos with us, the immanent and the economic Logos, are strictly the same.
Charles Hodge came to similar conclusions over a century earlier:
That the Latin and Protestant Churches, in opposition to the Greek Church, are authorized in teaching that the Spirit proceeds not from the Father only, but from the Father and the Son, is evident, because whatever is said in Scripture of the relation of the Spirit to the Father, is also said of his relation to the Son. He is said to be the ‘Spirit of the Father,’ and ‘Spirit of the Son;’ He is given or sent by the Son as well as by the Father; the Son is said to operate through the Spirit. The Spirit is no more said to send or to operate through the Son, than to send or operate through the Father. The relation, so far as revealed, is the same in the one case as in the other.
Bishop Pearson reasoned from the economic Trinity that just as the Father is never sent by the Son because the Father did not receive the Godhead from the Son but rather the Son received the Godhead from the Father, so too, the Father and the Son are never sent by the Holy Spirit because they did not receive the Godhead from the Holy Spirit, but rather the Holy Spirit received the Godhead from the Father and the Son. Therefore, the Scriptures attest that both the Father and the Son send the Holy Spirit. Karl Barth neatly summed up the importance of the economic Trinity for knowing anything about the immanent Trinity: “All our statements concerning what is called the immanent Trinity have been reached simply as confirmations or underlinings or, materially, as the indispensable premises of the economic Trinity.”
6. The filioque is the only way to preserve the real distinction between the Son and the Holy Spirit.
As mentioned briefly above, the divine persons are distinguished by “mutually opposed relations.” For example, the Father cannot at the same time be His own Son, because begetting the Son is what distinguishes the Father as such. Systematic theology has traditionally averred that everything in God apart from these mutually opposed relations of origin, is “one.”
It has also traditionally been held that the activities causing the mutually opposed relations are the only “works of God” that are not the works of all three persons. As such they are works internal to God (opera ad intra). The opera ad intra are generation and spiration/procession. All works of God that terminate on a creature (i.e., are “outside” of God, or opera ad extra) are works of all three persons. These include the decrees, creation, providence, the covenants, redemption, the application of redemption, and consummation. Traditionally these external works of God can be “appropriated” or “ascribed” to one particular person (e.g., creation to the Father, redemption to the Son, and sanctification to the Holy Spirit), although in truth they are always and everywhere the works of all three persons.
The relations of generation and procession (the opera ad intra) in God produce personal attributes characterizing each of the three individual persons: The Father possesses paternity, is the only person who does an act of generation (begetting), is the only one who is unoriginated (ingenitus, innascible) and takes part in the active spiration (“breathing”; cf. “respiration”) of the Holy Spirit. The Son is the only person possessing the property of filiation or “sonship” or “begotteness,” and also participates in the active spiration of the Holy Spirit. The Holy Spirit is the only person who undergoes procession and passive spiration (i.e., He is the only person who is “breathed”).
The mutually opposed relations are those relations that cannot be simultaneously held by the same person (e.g., the Son cannot also be His own Father, and vice versa). The Father’s unoriginateness/unbegotteness, or His Paternity, is mutually opposed to the Son’s filiation or Sonship. The Spirit’s having been breathed or spirated (passive spiration) is opposed to the ones who do the breathing or active spiration, namely the Father and the Son. In this way all three persons stand in one mutually opposed relationship to the other two. The Father and the Son share a common attribute of active spiration, and this is not a mutually opposed relationship.
By imparting the properties unique to each individual person, the mutually opposed relations of origin provide the attributes distinguishing the persons from one another. If the Son does not also breathe or spirate the Holy Spirit, then there is no relation of opposition between the Son and the Holy Spirit (i.e., active spiration vs. passive spiration). Louis Berkhof summarizes:
The following points of distinction between the two may be noted, however: (1) Generation is the work of the Father only; spiration is the work of both the Father and the Son. (2) By generation the Son is enabled to take part in the work of spiration, but the Holy Spirit acquires no such power. (3) In logical order generation precedes spiration. It should be remembered, however, that all this implies no essential subordination of the Holy Spirit to the Son. In spiration as well as in generation there is a communication of the whole of the divine essence, so that the Holy Spirit is on an equality with the Father and the Son.
7. The analogy of spiration or “breathing” confirms the filioque.
If, as argued above, the economic trinity or economic missions of the divine persons reflect intratrinitarian realities, the eternal spiration or breathing of the Holy Spirit by the Son is reflected in Jesus’ impartation of the Holy Spirit through breathing (John 20:22). Turretin writes of John 20:22 that the “temporal procession presupposes the eternal.” Lewis Sperry Chafer comments in his systematic theology:
. . . the very term by which the third person in the trinity is designated WIND OR BREATH may, as to the third person, be designed, like the term Son applied to the second, to convey, though imperfectly, some intimation of that manner of being by which both are distinguished from each other, and from the Father; and it was a remarkable action of our Lord, and one certainly which does not discountenance this idea, that when he imparted the Holy Ghost to his disciples, ‘he BREATHED on them, and saith unto them, Receive ye the Holy Ghost’ (John 20:22).
8. The filioque is the only way to preserve the full deity of the Son.
With respect to the divine persons of the Trinity, the Eastern Churches tend to focus on the Father as the hypostatization (embodiment) of the divine essence, who as a result is the unique fountainhead of the deity, the one bearing the deity (theotetos). However, the West notes that when the Father, through generation (gennesis), puts the Son in possession of the divine nature, He also communicates to the Son the ability to spirate or breathe the Holy Spirit. In this way the Holy Spirit is breathed from both the Father and the Son. The Father does not communicate His characteristic of “unbegottenness” (ingenitus or inascibilitas) to the Son however, because the Son by definition must be “begotten.”
Calvin argues that the fact that the Holy Spirit also proceeds from the Son must be maintained in order to preserve the full deity of the Son (a very important point), and that the Holy Spirit also proceeds from the Son shows that the Son has the entire, full divine essence or substance.
Now they are compelled from their own presupposition to concede that the Spirit is of the Father alone, because if he is a derivation from the primal essence, which is proper only to the Father, he will not rightly be considered the Spirit of the Son. Yet this is disproved by Paul’s testimony, where he makes the Spirit common to Christ and the Father [Rom 8:9].
Furthermore, if the person of the Father is expunged from the Trinity, in what respect would he be different from the Son and the Spirit except that only he is God himself? They confess Christ to be God, and yet to differ from the Father. Conversely, there must be some mark of differentiation in order that the Father may not be the Son. Those who locate that mark in the essence clearly annihilate Christ’s true deity, which without essence, and indeed the whole essence, cannot exist. Certainly the Father would not be different from the Son unless he had in himself something unique, which was not shared with the Son. Now what can they find to distinguish him? If the distinction is in the essence, let them answer whether or not he has shared it with the Son. Indeed, this could not be done in part because it would be wicked to fashion a half-God. Besides, in this way they would basely tear apart the essence of God. It remains that the essence is wholly and perfectly common to Father and Son. If this is true, then there is indeed with respect to the essence no distinction of one from the other.
If they make rejoinder that the Father in bestowing essence nonetheless remains the sole God, in whom the essence is, Christ then will be a figurative God, a God in appearance and name only, not in reality itself.
Calvin also says:
Furthermore, this distinction is so far from contravening the utterly simple unity of God as to permit us to prove from it that the Son is one God with the Father because he shares with the Father one and the same Spirit; and that the Spirit is not something other than the Father and different from the Son, because he is the Spirit of the Father and the Son. For in each hypostasis the whole divine nature is understood, with this qualification—that to each belongs his own peculiar quality. The Father is wholly in the Son, the Son wholly in the Father, even as he himself declares: ‘I am in the Father and the Father in me.’ [John 14:10] And ecclesiastical writers do not concede that the one is separated from the other by any difference of essence. By these appellations which set forth the distinction (says Augustine) is signified their mutual relationships and now the very substance by which they are one. In this sense the opinions of the ancients are to be harmonized, which otherwise would seem somewhat to clash. Sometimes, indeed, they teach that the Father is the beginning of the Son; sometimes they declare that the Son has divinity and essence from himself, and thus has one beginning with the Father. . . . Therefore, when we speak simply of the Son without regard to the Father, we well and properly declare him to be of himself; and for this reason we call him the sole beginning. But when we mark the relation that he has with the Father, we rightly make the Father the beginning of the Son.
While Calvin’s doctrine of the theotetos of the Son may seem to mitigate against this understanding, later Reformed theologians make the distinction that the Father does not produce the divine essence of the Son, but rather communicates it to the Son. Louis Berkhof says that the generation of the Son by the Father
is a generation of the personal subsistence rather than of the divine essence of the Son. Some have spoken as if the Father generated the essence of the Son, but this is equivalent to saying that He generated His own essence, for the essence of both the Father and the Son is exactly the same. It is better to say that the Father generates the personal subsistence of the Son, but thereby also communicates to Him the divine essence in its entirety.
All of this to say that Calvin’s stress on the full deity of the Son is certainly support for the inclusion of the filioque in Reformed theology, and against its exclusion, since denial of the filioque has been associated with a subordination of the Son to the Father. This results in a subordination of the Son’s essence and deity, and not just the Son’s mission.
9. Denying the filioque results in denying crucial aspects of orthodox soteriology.
In the graduate Trinity course at Fordham University, Aristotle Papanikalaou insisted that the filioque is not only an issue of speculation concerning the inner workings of the Godhead, but it is also the doctrine of God’s life for us, pro nobis. In other words the filioque has implications for soteriology and God’s economy of salvation. Papanikalaou, who is Greek Orthodox, remarked,
“There is something lacking in trinitarian theology when you do not relate the Son and the Spirit together as does the filioque.”
If the aspect of salvation in which God comes to us and communicates himself to us (regeneration, indwelling, and sanctification by the Holy Spirit) is to be always and necessarily tied to the Son, Jesus Christ, then the Holy Spirit must be as completely the Spirit of Christ or of the Son as He is the Spirit of the Father. That is, the Holy Spirit cannot only come through the Son, but must proceed from the Son, as from a source. It is only in this way that the axiom “No one who denies the Son has the Father (1 John 2:23a)” is fully true. In fact, some who are trying to answer the question of salvation in other religions and communities outside the realm of the gospel appeal to a universal working of the Holy Spirit independent of the Word or the person of Jesus Christ.
Also, the fact that the filioque preserves the full deity of the Son bears on salvation since the Son must be fully and completely God in order for Him to be able to effect salvation. Athanasius made this same argument against the Arians in the fourth century. Since salvation is only ever from the LORD, Jesus Christ must be fully God as much as the Father, which the filioque is intended to aver.
Louis Berkhof cites key Arminians who held to a subordinatationist Christology that bordered on, if not became, neo-Arianism. The connection between Arminian theology and Arian christology is that the more that man can do to save himself, the less supernatural, divine power is needed. If man can do something to save himself, then salvation is not entirely dependent on the Almighty God. The divinity and transcendence of Christ decrease in direct proportion to the power of man to work something for his own salvation. That the Reformed tradition has always held the full and complete divinity of Christ as of utmost importance is seen from Calvin with his theototes of the Son, up to Karl Barth, who spends the second half of the first volume of his Church Dogmatics arguing for the full and complete divinity of Christ within the context of discussing the Trinity.
This is related to the filioque insofar as the filioque is an assertion of the full and complete divinity of the Son, as discussed above. The East alleges that the West is too “Christocentric,” a symptom of which is the filioque. Is not the preeminence of Christ a pillar of the Reformed tradition?
The Holy Spirit is the love of God poured out into our hearts (Rom 5:5)—this corresponds to the Augustinian idea that the Holy Spirit is the bond of love between the Father and the Son. Is there any love of God apart from Jesus Christ? Karl Barth argues for the necessity of the filioque in order to make sense of the work of the Holy Spirit in uniting humans to God and the intratrinitarian divine life:
‘And the Son’ means that not merely for us, but in God Himself, there is no possibility of an opening and readiness and capacity for God in man—for this is the work of the Holy Ghost in revelation—unless it comes from Him, the Father, who has revealed Himself in His Word, in Jesus Christ, and also, and no less necessarily, from Him who is His Word, from His Son, from Jesus Christ, who reveals the Father. . . . The Filioque expresses recognition of the communion between the Father and the Son. The Holy Spirit is the love which is the essence of the relation between these two modes of being of God. And recognition of this communion is no other than recognition of the basis and confirmation of the communion between God and man as a divine, eternal truth, created in revelation by the Holy Spirit. The intra-divine two-sided fellowship of the Spirit, which proceeds from the Father and the Son, is the basis of the fact that there is in revelation or fellowship in which not only is God there for man but in very truth—this is the donum Spiritus sancti [gift of the Holy Spirit]—man is also there for God. Conversely, in this fellowship in revelation which is created between God and man by the Holy Spirit there may be discerned the fellowship in God Himself, the eternal love of God: discerned as the mystery, surpassing all understanding, of the possibility of this reality of revelation; discerned as the one God in the mode of being of the Spirit. . . . This whole insight and outlook is lost when the immanent Filioque is denied. If the Spirit is also the Spirit of the Son only in revelation and for faith, if He is only the Spirit of the Father in eternity, i.e., in His true and original reality, then the fellowship of the Spirit between God and man is without objective ground and content [i.e., Jesus Christ]. Even though revealed and believed, it is a purely temporal truth with no eternal basis, so to speak, in itself. No matter, then, what we may have to say about the communion between God and man, it does not have in this case a guarantee in the communion between God the Father and God the Son as the eternal content of its temporal reality. Does not this mean an emptying of revelation?
A final practical ecclesiological note can also be made regarding the filioque. The Eastern formulation runs the danger of suggesting an unnatural distance between the Son and the Holy Spirit, leading to the possibility that even in personal worship an emphasis on more mystical, Spirit-inspired experience might be pursued to the neglect of an accompanying rationally understandable adoration of Christ as Lord.
Excerpt taken from : How Important Is The Filioque For Reformed Orthodoxy? Westminster Theological Journal Volume 66 (vnp.66.1.159). Westminster Theological Seminary.