don't love each other for sinning
Allah says: The idols you worship besides Allah only create love among you in this worldly life (Al-Ankabut: 25)
Also: Woe to me, if only I had not taken so-and-so as a close friend (Al-Furqan: 28)
And: Close friends on that day will be enemies to one another, except for those who are mindful of Allah (Az-Zukhruf: 67)
(from Syajaratul Ma‘arif, Syaikh al-‘Izz bin Abdus Salam)