John 14:11

Irenaeus Against Heresies Book V

How, then, could the fruit of ignorance and defect sustain Him who contains the knowledge of all things, and is true and perfect? Or how could that creation which was concealed from the Father, and far removed from Him, have sustained His Word? And if this world were made by the angels (it matters not whether we suppose their ignorance or their cognizance of the Supreme God), when the Lord declared, "For I am in the Father, and the Father in Me,"[156]

Tertullian Against Praxeas

But the Word was formed by the Spirit, and (if I may so express myself) the Spirit is the body of the Word. The Word, therefore, is both always in the Father, as He says, "I am in the Father; "[89]

Tertullian Against Praxeas

He ought rather to have said: "Believest thou not that I am the Father? "With what view else did He so emphatically dwell on this point, if it Were not to clear up that which He wished men to understand-namely, that He was the Son? And then, again, by saying, "Believest thou not that I am in the Father, and the Father in me,"[340]

Origen Against Celsus Book VIII

he would not have supposed that we worship any other besides Him who is the Supreme God. "For," says He, "My Father is in Me, and I in Him."[22]

Dionysius Against the Sabellians

For if the Son was made, there was a time when He was not; but He always was, if, as He Himself declares,[3]