1 John 2:9

2:9 The one who says he is in the light but still hates his fellow Christian is still in the darkness.

1 John 4:20

4:20 If anyone says “I love God” and yet hates his fellow Christian, he is a liar, because the one who does not love his fellow Christian whom he has seen cannot love God whom he has not seen.

1 John 3:12

3:12 not like Cain who was of the evil one and brutally murdered his brother. And why did he murder him? Because his deeds were evil, but his brother’s were righteous.