1 John 2:3-5 (New International Version)

 ³We know that we have come to know him if we obey his commands. ⁴The man who says, "I know him," but does not do what he commands is a liar, and the truth is not in him. ⁵But if anyone obeys his word, God's love^[a] is truly made complete in him. This is how we know we are in him: