One of the words that jumped out at me, after reading this passage was "know".
verse 2 ".... know the Spirit of God..."
verse 6 "... he that knoweth God heareth us.."
verse 7 "... everyone that loveth is born of God and knoweth God"
verse 8 " He that loveth not, knoweth not God..."
verse 16 "And we have known and believed the love that God hath to us. God is love; and he that dwelleth in love dwelleth in God, and God in him.
Then I read verse 20.
verse 20 "If a man say, I love God, and hateth his brother, he is a liar: for he that loveth not his brother whom he hath seen, how can he love God whom he hath not seen?
In short, we must love our brother and sister, or we cannot love Him. If we cannot love Him, we can never know Him.
Bron Dutton