1 John 1:7-9 (KJV):

    7but if we walk in the light, as he is in the light, we have fellowship one with  another, and the blood of Jesus Christ his Son cleanseth us from all sin. 8If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.