1 John 4:20

If any one may say, I love God with divine love, and may hate his brother, he is a liar: for the one not loving his brother whom he has seen, with divine love, is not able to love God, whom he has not seen, with divine love.

1 John 2:4

The one saying, I have known him, and keeping not his commandments, is a liar, and the truth is not in him;

1 John 2:9

The one saying that he is in the light, and hating his brother, is in the darkness until now.

1 John 3:17

Whosoever may have the sustenance of the world, and see his brother having need, and shut up his sympathies from him, how dwells the divine love of God in him?

1 John 4:12

No one has seen God at any time; if we love one another with divine love, God abides in us, and his divine love has been made perfect in us.

1 John 2:11

But the one hating his brother is in darkness, and walks about in darkness, and does not know whither he is going, because the darkness has blinded his eyes.

1 Peter 1:8

whom you not seeing, love with divine love; on whom, not looking, but believing, you rejoice with joy unspeakable and full of glory:

1 John 1:6

If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:

Treasury of Scripture Knowledge

Summary

If a man say, I love God, and hateth his brother, he is a liar: for he that loveth not his brother whom he hath seen, how can he love God whom he hath not seen?

Bible References

A man

1 John 2:4
The one saying, I have known him, and keeping not his commandments, is a liar, and the truth is not in him;
1 John 3:17
Whosoever may have the sustenance of the world, and see his brother having need, and shut up his sympathies from him, how dwells the divine love of God in him?

Not

1 John 4:12
No one has seen God at any time; if we love one another with divine love, God abides in us, and his divine love has been made perfect in us.

General references

Matthew 22:40
On these two commandments hang all the law, and the prophets.
Matthew 25:42
For I was hungry, and you gave me nothing to eat: I was thirsty, and you gave me nothing to drink:
John 13:35
in this shall all know that you are my disciples, if you may have divine love one with another.
John 14:15
If you love me, keep my commandments.
Hebrews 13:1
Let brotherly love continue.