Psalm 44:21  Shall not God search this out?  for he knoweth the secrets of the heart.

Psalm 66:18  If I regard iniquity in my heart, the Lord will not hear me:

Psalm 139:23-24  Search me, O God, and know my heart:  try me, and know my thoughts:  And see if there be any wicked way in me, and lead me in the way everlasting.

Proverbs 28:13  He that covereth his sins shall not prosper: but whoso confesseth and forsaketh them shall have mercy.

I John 1:9  If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.