The Trinity

Douglas F. Kelly, Systematic Theology, vol. 1 555–562.

Practical application of Trinitarian doctrine
We shall consider, among many possible applications, how the reality of the Holy Trinity makes possible: (a) our sharing in the Trinitarian life, and (b) a fruitful approach to the ancient (and modern) problem of ‘the one and the many.’
(a) Our sharing in the Trinitarian life
We have noted from the start of this work that God is known in community. This is not least because God is community within Himself; for Him to be is to be in relationship within His own Being from eternity to eternity. And God has created us from the beginning to be in a community of relationship to Himself and to one another. Another way to state this would be the words of Jesus: ‘And this is eternal life, that they might know thee, the only true God, and Jesus Christ whom thou hast sent’ (John 17:3).
In Matthew 11:27, we are told that ‘only the Son knows the Father’ and that ‘the Son reveals the Father to whom he will’. In John 14:9, Jesus says to Philip, ‘He who hath seen me hath seen the Father.’ That is, the Son has come down to earth to do all that was necessary to lift us up to a true knowledge of the Father, so that we share in the Son’s knowledge of the Father.
Saint Irenaeus in the late second century taught that we know God through sharing in the knowledge He has of Himself.129 Hilary said the same: ‘To the Son only is he known, for no one knows the Father except the Son and he to whom the Son wills to reveal him, nor yet the Son except the Father. Each has perfect and complete knowledge of the Other. Therefore, since no one knows the Father except the Son, let our thoughts of the Father be at one with the only faithful witness who reveals him.’130
Athanasius saw that our true knowledge of God must conform to Jesus Christ since He is the perfect image of God, the one Form or Eidos of Godhead.131 He stated that ‘The Form of the Godhead of the Father is the Being of the Son.’132 T. F. Torrance comments on Athanasius’ and Hilary’s expression of this truth:
Careful examination [i.e. of passages such as Luke 10:22 and Matthew 11:27] disclosed that the mutual relation of knowing between the Father and the Son … involved a mutual relation of being between them as well, and not only between the eternal Son and the Father but between the incarnate Son and the Father. This implies that we are given access to the closed circle of divine knowing between the Father and the Son only through cognitive union with Christ, that is only through an interrelation of knowing and being between us and the incarnate Son, although in our case this union is one of participation through grace and not one of nature.133
To make this sharing (in a way appropriate to creatures) in the divine Being and knowing, the Son of God took on our flesh, lived the holy life of obedience to the Father that we should have lived, atoned for our sins on the cross, raised us with Him in His bodily resurrection, ‘seated us in heavenly places’ (Eph. 2:6) with Him, and thus prepared the way for us to share in His true knowledge and love of the heavenly Father. From His glorious seat on high with the Father, He and the Father sent down to us the Holy Spirit to baptize us into this union with incarnate deity in being and knowledge. Torrance describes this movement clearly: ‘It is the Holy Spirit who actualises the self-giving of God in Jesus Christ and so enables us to receive and apprehend what is beyond ourselves altogether, the self-knowledge of God himself incarnate among us in Christ. This is what is actualised in the faith and worship and obedient devotion of the Church to God’s self-communication through the Son and in the Spirit.’134
Cyril of Alexandria wrote in his Dialogues on the Trinity, ‘Sanctified by its union with the Spirit, the flesh is raised to the divine Word, and through Him to the Father … It is the Spirit who unites us and so to speak, makes us sympathize with God; His reception makes us partakers of the divine nature, and we receive this from the Son, and, through the Son from the Father.’135 In other words, the stupendous grace of the generous God is such that He gives us knowledge—thus, saving relationship—with Himself, as He comes to us in Christ and in the Holy Spirit. Stăniloae explains:
In Christ the divine hypostasis is accessible to us on our own human level for the sake of full communion. Christ overcame in himself the interval between divinity and humanity, and between himself as God and ourselves … The Son of God became man in order that, through our own movement, he might help us overcome the temporal interval that separates us from full communion with God. In some fashion he performs this movement together with us and because of this he finds himself within this interval still, although on the other hand he is above it.136
This saving knowledge in which we are given to share by divine and immeasurable grace is brought down from God and takes us up to God. To refer again to Stăniloae:
Within the reciprocal knowledge of the Trinitarian persons as infinite subjects there is given in God, simultaneously with eternity, the basis for the possibility of the knowledge of other subjects, and hence also of the creation of subjects who are limited in themselves. Through this love which gives him knowledge, God comes down to the interiority found in created limited subjects, yet by means of his love God raises them up at the same time to their inferiority in him, thus opening up for them the road towards his knowledge.137
John Calvin on our true knowledge of God in Christ
The Reformer John Calvin was in line with the best of the Church Fathers, and with Holy Scripture, in teaching that we truly know God through Christ and in the Holy Spirit. He states that although we are separated from God by space and time, the Holy Spirit overcomes those barriers to grant us true union with Christ, whom to know is to know God in His innermost Being.
Ronald S. Wallace in his Calvin’s Doctrine of the Christian Life has summarized correctly Calvin’s teaching on this important application of Trinitarian doctrine. I shall summarize what he brings out, with copious references to the statements of Calvin. He shows that the Holy Spirit as the omnipresence of God unites us believing humans to the humanity of the Lord, so that to know him is to know the Father:
Calvin teaches that our knowledge of the Father is possible only through union with Christ:
Therefore, to share with us what he has received from the Father, he had to become ours and to dwell within us. For this reason, he is called ‘our Head’ (Eph. 4:15), and ‘the first-born among many brethren’ (Rom. 8:29). We also, in turn, are said to be ‘engrafted into him’ (Rom. 11:17) and to ‘put on Christ’ (Gal. 3:27): for, as I have said, all that he possesses is nothing to us until we grow into one body with him.138
It is true that we obtain this by faith. We know, moreover, that he benefits only those whose ‘Head’ he is, for … we ‘have put him on’ (Gal. 3:27). This union alone ensures that, as far as we are concerned, he has not unprofitably come with the name of Savior. The same purpose is served by that sacred wedlock through which we are made flesh of his flesh and bone of his bone, and thus one with him. But he unites us to himself by the Spirit alone.139
Calvin is clear that our union with Christ occurs through the supernatural operation in us of the Holy Spirit, who thus united us to Christ, and through him brings us to the Father. Again, he is close to Cyril of Alexandria in this teaching: ‘The fullness given in us by the Father and the Son is realized (as one fullness) … by the Holy Spirit who fills us with divine charisms through Himself, and makes us partakers of the ineffable nature.’140
In Calvin’s words: ‘It is therefore the Holy Spirit alone who can effect this union [i.e. between God and mankind], for it is the Holy Spirit alone who can so join things in Heaven and things on earth that heavenly things can be grasped by human minds and that the life and virtue of what is in Heaven can be shared by those who are yet on earth. It is the Holy Spirit alone who can bring into real being that wonderful relation of mystery between Christ’s heavenly body and His Church on earth which is so clearly depicted in the act of participation in the Lord’s Supper and in Baptism …’141
Here, Calvin is very close to Cyril of Alexandria who influenced him considerably. Cyril wrote: ‘If, perchance, we were to be deprived of the Spirit, we would not even recognize that God might be in us; and had we not been enriched by the Spirit who places us among the children of God, we would in no way be children of God. For it is the Spirit who joins us together and so to speak, unites us to God; once He is received, we become partakers of the divine nature. And thus, through the Son and in the Son, we receive the Father Himself.’142
Calvin then shows that this participation through union with Christ is never apart from personal faith:
Faith enables us to partake of the life made available through the death of Christ. But all this is possible only because faith actually unites us to Christ and inserts us into His body, creating the bond that enables us to receive, possess and enjoy Christ Himself—for the blessings which are His gifts cannot be received and enjoyed by us apart from communion with Himself by faith.143
Faith is thus an entirely supernatural gift—a new capacity created within man whereby what is in Heaven is really possessed and enjoyed by him. It effects such a secret and wonderful communion with Christ that even though Jesus Christ remains entire in Heaven, He is nevertheless grasped so firmly and possessed so completely that He may be said actually to dwell in our hearts.144
Faith has the power to reach through the humanity of Jesus even God Himself. Faith is able to rise from the flesh of Christ to His divinity, and to penetrate above all the heavens, even to those mysteries which the angels behold and adore. Faith unites man to God and makes God to dwell in man.145
We can summarize this teaching of Calvin on our experience of the whole Trinity in Christian salvation by referring once more to Cyril of Alexandria, whom Calvin so often followed. Cyril expresses the Christian experience of communion with God in terms of beauty: ‘To this beauty, we too have been conformed, by receiving a filial imprint through the Son in the Spirit.’146
(b) A fruitful approach to the one and many problem
One of the most ancient questions in philosophy and in the ordering of human society is the question of the one and the many; which is more basic: the one (the overarching structure) or the many (the individual)? Far from remaining a merely philosophical problem, it has always been—and still is—a major problem for the political, governmental ordering of human society.
More than one Trinitarian theologian has seen that there is a fruitful approach to this question in the eternal existence of the Creator, who is at the same time both One (one Monarchy) and Many (three Persons). Colin Gunton in his 1992 Bampton Lectures to the University of Oxford has seen the right answer to this question as lying in the reality of God as one and many at the same time.147
He argues that in Western society since the Nominalist movement of the fourteenth century, God has been displaced by other universals.148 This movement is destructive for human society,149 for it leaves society without a balance between individual freedom and governmental structure. When the many are reduced to one, totalitarianism inevitably ensues.150 As early as the fourteenth century, William of Occam was denying creational balance between the one and the many for the ordering of human life in society.151 By excluding relationship to God within His creational orders, mankind was left with a sort of individualism that required collectivism.152 Thus, modernism tended to suppress the particular (or the many).153 This has led to our present malaise of soul-less homogeneity in Western consumer society.154 Out of this ‘knee-jerk’ homogeneity has come the late twentieth-century ‘Political Correctness’ movement, which—not unlike the medieval Spanish Inquisition—sternly forbids, and frequently punishes, the expression of an alternative point of view to the reigning secularist, pluralistic orthodoxy of jaded Western society.
In displacing the true one and the many—the Triune God—modern society has ‘liberated’ society from Christianity into a depressing bondage of the shifting consensus of the secularist elite, who control to some degree the Western media. This is a bondage to the one, which brooks no rivals. In displacing the reality of God and eternity, it has focused all attention and all hopes on our brief life in this world. It has led to the widespread belief in the omnicompetence of politics,155 which has produced massive intolerance by those who preach tolerance, or—in effect—a selective tolerance.156
Gunton shows that there is no way out of this horrid morass except a return to faith and obedience in the Holy Trinity: the One and the Many, whose presence and Word gives a fruitful and wholesome balance between liberty (of the many) and ordered structure (of the one moral reality).
From a rather different cultural and political point of view, though with some important theological commonalities, R. J. Rushdoony several years earlier had also seen the Trinity as the answer to the inescapable answer to the one and many problem that always confronts all humans. In his study, The One and the Many, he writes:
Since both the one and the many are equally ultimate in God, it immediately becomes apparent that these two seemingly contradictory aspects of being do not cancel one another but are equally basic to the ontological trinity, one God, three persons. Again, since temporal unity and plurality are the products and creation of this triune God, neither the unity nor the plurality can demand the sacrifice of the other to itself. Thus, man and government are equally aspects of created reality. The locus of Christianity is both the believer and the church; they are not independent of or prior to one another. The wishes of husband and wife do not take priority over marriage, nor does the institution of marriage have primacy over the partners to it; marriage indeed is a type of eternal reality (Eph. 5:22), but man is himself created in the image of God (Gen. 1:26, 27). Education must be geared both to the individual and to society, but, above all, to God.157
Rushdoony explains the details of what this balance means in practical terms:
In orthodox Trinitarian Christianity, the problem of the one and the many is resolved. Unity and plurality are equally ultimate in the Godhead. The temporal unity and plurality is on a basis of equal validity. There is thus no basic conflict between individual and community. The individual lives in community, and the community flourishes as the individual finds himself and grows in terms of consistently Christian faith. Instead of a basic philosophical hostility between government, believer and church, person and family, there is a necessary coexistence. Neither the one nor the many is reducible to the other. They cannot seek the obliteration of the other, for it involves self-obliteration. The Augustinian and Calvinistic faith, with its hostility to subordinationism, holds, if developed, the possibilities for true social order, and to the extent that Augustinianism and Calvinism have been followed, Western culture has developed both freedom and order.158
Elsewhere, Rushdoony suggests some of the products of this kind of Trinitarian balance between the one and the many as: parliaments, universities and constitutions.159 In his The Nature of the American System, he traces the constitutional balance between structure (the one) and local and personal liberties (the many) that took deep root in the American colonies back to the faith of most of the founding fathers in the Holy Trinity. He argues with considerable persuasiveness that insofar as faith in the Trinity is eclipsed in society, an imbalance towards the one (eventually resulting in various forms of political totalitarianism) is bound to follow.
Although not of the same theological persuasion in various respects, Colin Gunton’s assessment of our contemporary dilemma is not essentially different—at least as to the origin of our current problem: formerly, perhaps, totalitarian Marxism in the East, but now a sort of soulless consumerist materialism (as equally hostile to the reality of the Holy Trinity as were the communists)—which is equally destructive of God-given human values—in the West, as Del Noce has shown us.160
A return to living faith in and cordial obedience to the Holy Trinity is the only hope for our sick society of both East and West. The high mission of God’s Church is to point the way to restoration for every nation and culture; not as its main goal (which is always the glorification of God in the eternal salvation and sanctification of sinners into the body of Christ), but as a fruitful by-product or perhaps a certain temporal foretaste of a future cosmic renewal (which is not unrelated to final manifestation of ‘the glorious liberty of the children of God’—Rom. 8:21). But until that great breaking of eternity into time, many different periods of history in many different cultures have shown that God-centered lives tend towards mercy and justice, beauty and truth. Thus, when large minorities (even when far less than a majority) in a land are ‘walking in the Spirit’, reformed and healthy societies (imperfect as they always are before the final ‘manifestation of the sons of God’) follow, as the day follows the night.
Of course, restoration within human cultures over the centuries of Christian influence has its ebbs and flows. But even when the tide of vital faith and godly practice seems to be at a low point in some nations, it may be rapidly rising in others (as seems to be the case today with the declining Western world, which has largely jettisoned its Christian belief—and is losing population—and the rising Christian spirituality in the African, Asian and Southern American spheres—which are growing in population). Yet through all these varied conditions which are constantly changing from time to time and land to land, one majestic reality overarches them all, and makes life worth living in any of them at any time. It is a glorious reality open to all who wish it: the communion of holy love that constitutes the very life of the Triune God is available to those who recognize that they are unworthy and cannot save themselves from sin and death, and are willing to cry out to God for mercy. In a word, eternal life, lasting pardon and true liberation from the Father, through the Son and in the Spirit are gifts of the gospel that may still be received by simple faith.
Isaiah says that living waters can be purchased ‘without money and without price’ (Isa. 55:1). The Puritan biblical commentator, Matthew Henry, beautifully expounds this free invitation to those who can offer nothing in return:
… Though we be never so miserable and empty—empty of knowledge, empty of grace (tohu and wohu, Gen. 1:2 [i.e. transliterations of two Hebrew words—‘without form and void’]) yet we have received from Christ, without money and without price (Isa. 55:1). The poor and the maimed are fetched in to the feast. Former barrenness and badness is no bar to this grace if we be truly penitent and come for grace. Poor and blind and naked are invited to Christ (Rev. 3:17, 18). Paul that had been a blasphemer yet received this grace. There’s gifts received even for the rebellious (Ps. 68:18).161
Jesus says in the Gospel of John: ‘And ye now therefore have sorrow; but I will see you again, and your heart shall rejoice, and your joy no man taketh from you. And in that day ye shall ask me nothing. Verily, verily, I say unto you, Whatsoever ye shall ask the Father in my name, he will give it you. Hitherto have ye asked nothing in my name ask, and ye shall receive, that your joy may be full’ (John 16:22–24).
And above a changing world, the unchanging promise of our Lord still stands: ‘For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved’ (John 3:16, 17).

Douglas F. Kelly, Systematic Theology, vol. 1 (Ross-shire, Scotland: Mentor, 2008), 555–562.