All religions have some truth in them, but none has the whole truth; all are created in time and finally decline and perish. Mahomed himself never pretended that the Koran was the last message of God and there would be no other. God and Truth outlast these religions and manifest themselves anew in whatever way or form the Divine Wisdom chooses.
When the last moment arrives, praise and blame will be the same to you, to me, and to others. We are here to work, and will have to leave all when the call comes.