An important part of being a Christian is loving other Christians.
1 John 2:
9 If anyone claims, “I am living in the light,” but hates a fellow believer, that person is still living in darkness. 10 Anyone who loves a fellow believer[b] is living in the light and does not cause others to stumble. 11 But anyone who hates a fellow believer is still living and walking in darkness. Such a person does not know the way to go, having been blinded by the darkness.