Irenaeus, The Glory of the Incarnation

“Their doctrine departs from Him who is truly God, being ignorant that His only-begotten Word, who is always present with the human race, united to and mingled with His own creation, according to the Father’s pleasure, and who became flesh, is Himself Jesus Christ our Lord, who did also suffer for us, and rose again on our behalf, and who will come again in the glory of His Father, to raise up all flesh, and for the manifestation of salvation, and to apply the rule of just judgment to all who were made by Him.

"There is therefore, as I have pointed out, one God the Father, and one Christ Jesus, who came by means of the whole arrangements connected with Him, and gathered together all things in Himself. But in every respect, too, He is man, the formation of God.

"And thus He took up man into Himself, the invisible becoming visible, the incomprehensible being made comprehensible, the impassible becoming capable of suffering, and the Word being made man, thus summing up all things in Himself so that as in super-celestial, spiritual, and invisible things, the Word of God is supreme, so also in things visible and corporeal He might possess the supremacy, and, taking to Himself the pre-eminence, as well as constituting Himself Head of the Church, He might draw all things to Himself at the proper time.”

–Irenaeus of Lyons, Against Heresies, III.xvi.6.