Irenaeus — Commentary on Scripture

A lie has no fellowship with the truth, any more than light with darkness. The presence of one excludes the other.

Wherefore we have need of the dew of God, that we be not consumed by fire, nor be rendered unfruitful, and that where we have an accuser there we may have also an Advocate,

Against Heresies Book III

1 John 2:18

Know ye therefore, that every lie is from without, and is not of the truth. Who is a liar, but he that denieth that Jesus is the Christ? This is Antichrist.".
foreseeing by the Spirit those weak-minded persons who should be led astray.

Against Heresies Book III

1 John 4:1

Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God; and every spirit which separates Jesus Christ is not of God, but is of antichrist."

Against Heresies Book III

1 John 5:1

These words agree with what was said in the Gospel, that "the Word was made flesh, and dwelt among us." Wherefore he again exclaims in his Epistle, "Every one that believeth that Jesus is the Christ, has been born of God;" knowing Jesus Christ to be one and the same, to whom the gates of heaven were opened, because of His taking upon Him flesh: who shall also come in the same flesh in which He suffered, revealing the glory of the Father.

Against Heresies Book 3

1 John 5:6

, and calls them into his own kingdom? And why is his goodness, which does not save all

Against Heresies Book IV