1 Corinthians 8:12

But in sinning against your brothers in this way and wounding their too scrupulous consciences, you are really sinning against Christ.

1 John 3:15

Whoever hates his brother is a murderer, and you know that no murderer can have eternal life remain in his heart.

Treasury of Scripture Knowledge

Summary

And Jonathan spake good of David unto Saul his father, and said unto him, Let not the king sin against his servant, against David; because he hath not sinned against thee, and because his works have been to theeward very good:

Bible References

Sin against

1 Corinthians 8:12
But in sinning against your brothers in this way and wounding their too scrupulous consciences, you are really sinning against Christ.
1 John 3:15
Whoever hates his brother is a murderer, and you know that no murderer can have eternal life remain in his heart.