But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus Christ, his Son, cleanses us from all sin.
Verse 1 John 1:3 , chapter 2, "And hereby we do know that we know Him." Now, if I say I know God and don't keep His commandments, I am a liar. But here's how I can know that I really know Him, if I keep His commandments.