As Christ the Lord who saved us, though He was first a Spirit became flesh, and thus called us, so shall we also receive the reward in this flesh. (IX).
Irenaeus is really the first church father who gives us a clear picture what the early church believed concerning the incarnation of the Word.
1. But there are some who say that Jesus was merely a receptacle of Christ, upon whom the Christ, as a dove, descended from above, and that when He had declared the unnameable Father He entered into the Pleroma in an incomprehensible and invisible manner: for that He was not comprehended, not only by men, but not even by those powers and virtues which are in heaven, and that Jesus was the Son, but that Christ was the Father, and the Father of Christ, God; while others say that He merely suffered in outward appearance, being naturally impassible. (III, 16).