1 John 4:20

If a man says, I have love for God, and has hate for his brother, his words are false: for how is the man who has no love for his brother whom he has seen, able to have love for God whom he has not seen?

1 John 2:4

The man who says, I have knowledge of him, and does not keep his laws, is false, and there is nothing true in him:

1 John 2:9

He who says that he is in the light, and has hate in his heart for his brother, is still in the dark.

1 John 3:17

But if a man has this world's goods, and sees that his brother is in need, and keeps his heart shut against his brother, how is it possible for the love of God to be in him?

1 John 4:12

No man has ever seen God: if we have love for one another, God is in us and his love is made complete in us:

1 John 2:11

But he who has hate for his brother is in the dark, walking in the dark with no knowledge of where he is going, unable to see because of the dark.

1 Peter 1:8

To whom your love is given, though you have not seen him; and the faith which you have in him, though you do not see him now, gives you joy greater than words and full of glory:

1 John 1:6

If we say we are joined to him, and are walking still in the dark, our words are false and our acts are untrue:

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 man who says, I have knowledge of him, and does not keep his laws, is false, and there is nothing true in him:
1 John 3:17
But if a man has this world's goods, and sees that his brother is in need, and keeps his heart shut against his brother, how is it possible for the love of God to be in him?

Not

1 John 4:12
No man has ever seen God: if we have love for one another, God is in us and his love is made complete in us:

General references

Matthew 22:40
On these two rules all the law and the prophets are based.
Matthew 25:42
For I was in need of food, and you gave it not to me; I was in need of drink, and you gave it not to me:
John 13:35
By this it will be clear to all men that you are my disciples, if you have love one for another.
John 14:15
If you have love for me, you will keep my laws.
Hebrews 13:1
Go on loving your brothers in the faith.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain