KJV
1Jn 2:4  He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. 
1Jn 2:5  But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him. 

WEB
1Jn 2:4  One who says, “I know him,” and doesn’t keep his commandments, is a liar, and the truth isn’t in him. 
1Jn 2:5  But whoever keeps his word, God’s love has most certainly been perfected in him. This is how we know that we are in him: