1 John 3:15-19, 23

Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him. Hereby know we love, because he laid down his life for us: and we ought to lay down our lives for the brethren. But whoso hath the world’s goods, and beholdeth his brother in need, and shutteth up his compassion from him, how doth the love of God abide in him? My little children, let us not love in word, neither with the tongue; but in deed and truth. Hereby shall we know that we are of the truth, and shall assure our heart before him

And this is his commandment, that we should believe in the name of his Son Jesus Christ, and love one another, even as he gave us commandment.