But Jesus, knowing their thoughts, said, "Why do you think evil in your hearts?", (Matthew 9:4)
Our actions may be saying one thing, while our hearts may be shouting another. And eventually our actions will succumb to our hearts. Our hearts are the roots of who we are. 1 Samuel 16:7 clearly tells us, "For the Lord does not see as man sees; for man looks at the outward appearance, but the Lord looks at the heart." We can hide who we are to the world for a season, but we cannot hide who we are with the Lord at all. Therefore let us confess our sinful thoughts to the Lord as readily as we confess our sinful deeds. Confession will bring repentance and repentance will cause a change of mind and a change of mind will bring about a change of heart. And a changed heart is a merry heart. And Proverbs 17:22 tells us, "A merry heart does good, like medicine." Therefore, a change of heart will change your life.