1 John 2:9-10

2:9 The one who says he is in the light but still hates his fellow Christian is still in the darkness. 2:10 The one who loves his fellow Christian resides in the light, and there is no cause for stumbling in him.

1 John 3:15

3:15 Everyone who hates his fellow Christian is a murderer, and you know that no murderer has eternal life residing in him.

1 John 4:21

4:21 And the commandment we have from him is this: that the one who loves God should love his fellow Christian too.