1 John 3:15-19, 23

Everyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him. By this we know love, that he laid down his life for us, and we ought to lay down our lives for the brothers. But if anyone has the world’s goods and sees his brother in need, yet closes his heart against him, how does God’s love abide in him? Little children, let us not love in word or talk but in deed and in truth. By this we shall know that we are of the truth and reassure our heart before him

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