Abu Hamzah Anas bin Malik, radiyallahu 'anhu, who was the servant of the Messenger of Allah, sallallahu 'alayhi wasallam, reported that the Prophet, sallallahu 'alayhi wasallam, said:

"None of you truly believes (in Allah and in His religion) until he loves for his brother what he loves for himself"
[Al-Bukhari & Muslim]