 One of the most important aspects of our belief system, one of the greatest manifestations in the belief, in the system that Allah Subhanahu wa Ta'ala has gave to humanity is the belief in the Mahdi, the rightly guided, awaited saviour. Without the belief in the Mahdi, one's belief cannot be completed. One may not achieve the completion of faith without believing in the Mahdi. Hence the Prophet sallallahu alaihi wa sallam said, وَمَنْ اَنْكَرَهُ فَقَدْ اَنْكَرَنيِ The one who rejects the Mahdi, the one who does not recognize the Mahdi, is like the one who has rejected me, is like the one who does not recognize me. Allah Subhanahu wa Ta'ala has given us a set of beliefs, in order for us to achieve the true faith that God wants us, we must complete this entire set. We cannot pick and choose. I want to believe in this aspect, but I disregard other aspects. And the greatest lesson that Allah has given us to humanity in the Holy Quran is the example of shaitan, where Allah Subhanahu wa Ta'ala instructed him to prostrate to Adam. He said, Oh Allah, spare me. Give me a different test. Spare me from prostrating to Adam, and I shall worship you in a way no other being has worshiped, that Allah accept his offer. Allah Subhanahu wa Ta'ala told him, Iblis, the name of the devil, worship me the way I want, not the way you want, because the minute that you form your belief system based on your own desires, based on your own wants, you're no longer believing in the one true Allah Subhanahu wa Ta'ala, the way he wanted you to believe in. We can only achieve the completion of faith by believing in Allah Subhanahu wa Ta'ala, the way he has wanted. That is why our greatest mission and our greatest challenge in this life is to form the correct beliefs that Allah Subhanahu wa Ta'ala wants from us.