1 John 1:8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
note from Jamieson-Fauset-Brown: that we have no sin- "Have," not "have had," must refer not to the past sinful life while unconverted, but to the present state wherein believers have sin even still.
We are only perfected, in the literal sense of the word, in the final redemption of the saints... when we all go home.