1 John 2:3 in the World English Bible
This is how we know that we know him: if we keep his commandments.
Context
2 And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.
3 And hereby we do know that we know him, if we keep his commandments.
4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.