All perfect praise be to Allah, The Lord of the Worlds, and may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
Islamic Sharia made it an obligation on every discerning adult Muslim to know Allah with deep stable conviction on basis of valid intellectual evidence since Almighty Allah said, " Know, therefore, that there is no god but God,"{Mohammad, 19}. It is to believe in the meaning of the Two Testimonies of Faith(Bearing witness that there is no God worthy of worship except Allah, and that Mohammad is His salve and Messenger). In other words, affirming(Tasdeeq) Allah`s attributes of perfection and denying opposite attributes, and having deep conviction in the Message brought by Prophet Mohammad(PBUH) with acknowledgment and submission.
It is only acceptable that a Muslim has a deep conviction in the existence of Allah since having an iota of doubt in that regard would render his/her creed(Aqidah) null and void. Allah, The Exalted, said, " Their apostles said: "Is there a doubt about God, The Creator of the heavens and the earth? It is He Who invites you, in order that He may forgive you your sins and give you respite for a term appointed!"{Ibrahim, 10}. He, The Almighty, also said, " But most of them follow nothing but fancy: truly fancy can be of no avail against truth. Verily God is well aware of all that they do."{Younis, 36}.
It should be pointed out that Islamic Sharia doesn`t require the discerning adult Muslim to know every specific detail about the evidence proving Allah`s existence, and that it suffices to know the general idea. In fact, this varies amongst the common based on their educational and intellectual status. Therefore, if one of them simply imitated the others and didn`t do any researching, then he is considered negligent, but remains a believer who has sinned.
In conclusion, in order for a Muslim to be a true believer, he must have a deep stable conviction in Allah, and it isn`t acceptable to base that conviction on mere unfounded fancy of the heart, even if the person in question adheres to the teachings of Sharia. And Allah knows best.
