33 Unless perchance we think that the Apostle did not keep to the principle of unity in that he said, And there are diversities of ministrations, and the same Lord, and there are diversities of workings, but the same God. So that because he referred ministrations to the Lord and workings to God, he does not appear to have understood one and the same Being in ministrations and operations. Learn how these members which minister are also members which work, when he says, You are the body of Christ, and of Him members indeed.
For God has set some in the Church, first apostles, in whom is the word of wisdom; secondly prophets, in whom is the gift of knowledge; thirdly teachers, in whom is the doctrine of faith; next mighty works, among which are the healing of diseases, the power to help, governments by the prophets, and gifts of either speaking or interpreting various kinds of tongues. Clearly these are the Church's agents of ministry and work of whom the body of Christ consists; and God has ordained them.
But perhaps you maintain that they have not been ordained by Christ, because it was God Who ordained them. But you shall hear what the Apostle says himself: Now to each one of us was the grace given according to the measure of the gift of Christ. And again, He that descended is the same also that ascended far above all the heavens that He might fill all things. And he gave some to be apostles; and some, prophets; and some, evangelists; and some, pastors and teachers; for the perfecting of the saints, for the work of ministering. Are not then the gifts of ministration Christ's, while they are also the gifts of God?
Source: On the Trinity (New Advent)