The Importance of the Theologia Unionis

Fine distinctions abound in the writings of the Reformed Scholastics, and many who are not versed in their language may think such things are really a matter of splitting hairs. When one reads through the various prolegomenas of Reformed theological works, one soon finds that theologia is a topic with many subdivisions and distinctions. The first division with which one is faced is the distinction between archetypal and ectypal theology. Archetypal theology is the perfect knowledge that God has of Himself. It is God as He really is and as He knows Himself in all perfection. Created beings cannot have this knowledge of God primarily because they are not infinite beings and therefore cannot contain infinite knowledge, for God is infinite and thus is the knowledge of Him.

What knowledge we can have of God is called ectypal theology. This is not an exact copy of the original knowledge but a trustworthy representation. It is all that created finite beings need to know, and can ever hope to know about God. Ectypal theology is further divided into theologia unionis or theology of union, theologia angelis or theology of angels, theologia beata or theology of the blessed, and theologia viatorum or theology of the pilgrims.  The latter three divisions all have to do with the theology or knowledge of God known to angels, men as they are perfected in heaven, and men as they are yet in their earthly pilgrimage.

Theology of union is the knowledge that the person of Christ has of God. The person of Christ has two natures one divine and one human. His divine nature can and does possess the archetypal knowledge, but how is this communicated to His human nature? It cannot share in this infinite knowledge because itself is finite and created. This is where the importance of the theology of union comes in. It is the attempt of the Reformed to keep the two natures distinct from each other without admixture according to the ancient orthodox formulations of Nicene and Post-Nicene Christianity. Christ, according to His human nature, had to receive the knowledge of God in ectypal form. Sebastian Rehnman writes in Divine Discourse: The Theological Methodology of John Owen, "If Christ according to his human nature had the infinite divine knowledge. there would be an interchange of attributes between the natures. However, according to the Reformed view, the integrity of the natures is preserved in their union, so the theology of Jesus Christ is, according to Owen, 'through the personal union' and 'revelations given to him from the Father.' Again Junius is followed: 'The theology which we call of union is the entire wisdom of divine things communicated to Christ the God-man, that is, as the Word made flesh, according to his humanity.' It is this knowledge that the Reformed theologians attempt to define with the concept of the theology of the Mediator or of union." (66, 67)

There is further importance to the theology of union besides preserving the integrity of both the divine and human natures of Christ. Rehnman writes:

The importance of the theology of the Mediator comes from its most intimate connection with all other forms of theology. It is, of course, a subdivision of ectypal theology, but a subdivision par excellence. As Christ is the Mediator between God and man and, the means of redemptive revelation, theologia unionis is the basis for all human theology. Owen writes:

Thus we confess Christ to be the light of the world and for this reason to all men, from the revelation of the Father, or his will concerning the obedience and salvation of sinners; not only because no divine truth was ever revealed without him, but because this shining light of Holy Scripture is sufficient to irradiate all men, to whom it reaches through providence of God, in the light of salvation.

So Christ brought the most perfect revelation to which nothing is to be added. Endued with perfect knowledge, he brought the perfect revelation of God's will to mankind. (67)

Thus it is shown that what at first appears to be a splitting of hairs is in reality a most important distinction. We have in this subdivision of ectypal theology a preservation of the orthodox doctrine of Christ, as well as a confirmation of what Luther called the theology of the cross, the idea that true theology on earth must be seen in light of the person and work of Christ. Christ makes true theology possible for sinners like you and me, and we cannot hope to have the beatific or blessed vision of God in heaven without the work of Christ. If hair-splitting distinctions preserve for us a right understanding of God, then I say, "The more the merrier!"