If someone says, "I love God," and hates his brother, he is a liar; for he who does not love his brother whom he has seen, how can he love God whom he has not seen?
1 John 4:20
Surrounding context
4:19 We love Him because He first loved us.
4:20 If someone says, "I love God," and hates his brother, he is a liar; for he who does not love his brother whom he has seen, how can he love God whom he has not seen?
4:21 And this commandment we have from Him: that he who loves God must love his brother also.