"Thou shalt be perfect with the LORD thy God." (Deuteronomy 18:13)
While we are not perfect in the flesh, our faith can and must be perfect in Christ. God provides truth in Christ through His living apostles to separate our faith from flesh to flame.
When our faith is governed by the grace and truth of God in Christ, then our repentance is sealed by faith in Him according to the terms and conditions of the covenant of Christ and we are no longer in bondage to the powers of this world with a defiled conscience.
For we have liberty from sin through covenant faith in Christ.
http://s8wministries.org/lesson.php?id=89&lesson=jesus-cleanses-through-his-truth-and-his-spirit&mid=34