(and the life was revealed, and we have seen, and testify, and declare to you the life, the eternal life, which was with the Father, and was revealed to us);
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.