Anas ibn Malik reported: The Messenger of Allah, peace and blessings be upon him, said:

None of you has faith until he loves for his brother ( other people) what he loves for himself.

Source: Sahih Bukhari 13, Grade: Muttafaqun Alayhi 

In another narration, the Prophet said:

None of you has faith until he loves for his brother or his neighbor what he loves for himself.

Source: Sahih Muslim 45, Grade: Sahih