“Herein is love made perfect in us, that we may have boldness in the day of judgment: because as He is, so are we in this world. There is no fear in love; but perfect love casts out fear: because fear has torment. He that fears is not made perfect in love. Let us love Him, because He first loved us. If a man say, I love God, and hates his brother, he is a liar: for he that loves not his brother whom he sees, how can he love God whom he sees not? And this commandment have we from Him, That he who loves God love his brother also.”
Source: Homilies on the First Epistle of John (New Advent)