AND MUHAMMAD is only an apostle; all the [other] apostles have passed away before him: if, then, he dies or is slain, will you turn about on your heels? But he that turns about on his heels can in no wise harm God - whereas God will requite all who are grateful [to Him].
Al-Imran (The Family of Imran) Verse 144
The Prophet said, "None of you will have faith till he wishes for his (Muslim) brother what he likes for himself."
Sahih Bukhari: Volume 1, Book 2, Number 12