1 John 1:10

Overview - 1 John 1
1	He describes the person of Christ, in whom we have eternal life, by a communion with God;
5	to which we must adjoin holiness of life, to testify the truth of that our communion and profession of faith, as also to assure us of the forgiveness of our sins by Christ's death.

1 John 1:10  (King James Version)
If we say that we have not sinned, we make him a liar, and his word is not in us.