Book XI. The Faith is one, even as God is One; but the faiths of heretics are many (§§ 1, 2). Hilary has now demonstrated the truth about Christ, so that it cannot be denied; it is attested also by miracles even in his own day (§ 3). The Arians preach another, a created Christ; and in making Christ a creature they proclaim another God, not a Father but a Creator (§ 4). The Son, as the Image, is of one nature with the Father; if He is inferior He is not the Image (§ 5). But the Arians explain the oneness away by arguments from His condescension to our estate (§ 6), and, even after His Resurrection, plead that He confesses His inequality.
They argue thus from 1 Cor. xv. 24-28, a passage to which the rest of this book is devoted (§§ 7, 8). But we must recognise the mysteriousness of the truth, accepting the two sides of it, both clearly revealed though we cannot reconcile them (§ 9). They regard only one aspect; Hilary in reply proves once more that Christ is both born from God, and Himself God (§§ 10-12). But at His Incarnation He began to have as Lord the God Who had been His Father eternally (§ 13), and when He said that He was ascending to His God, He spoke as when He calls us His brethren (§§ 14, 15).
Thus there are two senses in which God is the Father of Christ; and He Who is Father to Christ the Son is Lord to Christ the Servant (§§ 16, 17). And it was to Him as Servant that the Psalmist said, Your God has anointed You, the words would have no meaning if addressed to Him as Son (§§ 18, 19). It is through this lower nature that He is our Brother and God our Father, and He the Mediator (§ 20). But it is argued that His subjection at the last and the delivery of the kingdom to the Father is a proof of inequality.
The passage must be taken as a whole (§§ 21, 22). There are some truths which it is difficult for man to grasp, and if we misunderstand them we must not be ashamed to confess our error (§§ 23, 24). In this passage the Arians aid their case by changing the order of the prophecy (§§ 25-27). The end means a final and enduring state, not the coming to an end (§ 28), and though He delivers up the kingdom He does not cease to reign (§ 29). His subjection to the Father and the subjection of all things to Him is next considered; in one sense it is figurative language, in another it proves the unity of Father and Son.
The subjection of the Son means His partaking in the glory of the Father (§§ 30-36). The Transfiguration shows the glory of Christ's Body; a glory which the faithful shall share (§§ 37, 38). The righteous are His kingdom, which He, as Man, shall deliver to the Father, for By man came also the resurrection of the dead (§ 39). And at last God shall be all in all, humanity in Christ not being discarded, but glorified and received into the Godhead (§ 40). Christ, as well as St.
Paul, has foretold this (§§ 41, 42). The Arian misrepresentation of this truth is mere folly (§ 43). Any rational explanation must assume that God's majesty cannot be augmented, even as it cannot be measured (§§ 44, 45), while our reason is limited, and so contrasted with the Divine infinity. God cannot become greater than He was in becoming All in all. Father and Son, after as before, must Each be as He was (§§ 46-48). All was done for us that we might be glorified, being conformed to the likeness of Him Who is the Image of the Father (§ 49).
Source: On the Trinity (New Advent)