General questions about the religion of Islam

Religion has been ordained for the happiness of mankind in this world, and in the Hereafter.  The word "Islam" carries the meaning of submission and surrender to the will of Allah. This means that Islam is the religion of all prophets.

As for previous religions, they were all of them restricted.  They were sent to particular people and limited to particular times.  Islam alone is the one religion, which bears the seal of universality arid eternity.  This mark has adhered to it ever since the beginning of its call.  It is not therefore the idea of a moment afterwards cast upon it.