1 John 4:20

If one should say, I love God, and should be hating, his brother, false, is he; for, he that doth not love his brother, whom he hath seen, God, whom he hath not seen, he cannot love!

1 John 2:4

He that saith - I understand him! And, his commandments, is not keeping, is false, and, in him, the truth is not!

1 John 2:9

He that saith he is, in the light, and hateth, his brother, is, in the darkness, until even now!

1 John 3:17

But, whoso hath this world's goods, and beholdeth his brother having, need, and shutteth up his tender affections from him, how, is, the love of God, abiding in him?

1 John 4:12

Upon God, hath no one, at any time, gazed: If we love one another, God, in us, abideth, and, his love, hath been perfected within us.

1 John 2:11

Whereas, he that hateth his brother, in the darkness, dwelleth, and in the darkness, walketh; and knoweth not whither he is drifting, because the, darkness, hath blinded his eyes.

1 Peter 1:8

Whom, not having seen, ye love, on whom, though at present not looking, but believing, ye exult with joy unspeakable and filled with glory,

1 John 1:6

If we say - We have, fellowship, with him! and, in darkness, are walking, we are dealing falsely, and not doing 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
He that saith - I understand him! And, his commandments, is not keeping, is false, and, in him, the truth is not!
1 John 3:17
But, whoso hath this world's goods, and beholdeth his brother having, need, and shutteth up his tender affections from him, how, is, the love of God, abiding in him?

Not

1 John 4:12
Upon God, hath no one, at any time, gazed: If we love one another, God, in us, abideth, and, his love, hath been perfected within us.

General references

Matthew 22:40
In these two commandments, all the law, is contained, and the prophets.
Matthew 25:42
For I hungered, and ye gave me not to eat, and I was thirsty, and ye gave me not to drink,
John 13:35
By this, shall all men take knowledge, that, my disciples, ye are, - If ye have, love, one to another.
John 14:15
If ye be loving me, my commandments, ye will keep;
Hebrews 13:1
Let brotherly love continue.