My simple question to you is this: On what basis does the Qur’an invite a non-believer to believe in the message of the Qur’an? The answer, according to the Qur’an, is this:
Surely, In the creation of the heavens and the earth; in the alternation of the night and the day, in the sailing of the ships through the ocean for the profit of mankind; in the rain which Allah sends down from the skies, with which He revives the earth after its death and spreads in it all kinds of animals, in the change of the winds and the clouds between the sky and the earth that are made subservient, there are signs for rational people. (2:164)
The expression used towards the end of this verse in Arabic is “liqawmin ya‘qilun”, which means those who use their intellect, those who are rational etc. This verb has been used in the Qur’an at least fifty times. There are several other verbs which mean much the same thing are in addition to it.
The Qur’an, while giving the rationale of belief in the Hereafter, gives the following argument:
Shall We treat the Muslims as We treat the guilty? What is the matter with you; what kind of judgement do you make? (68:35-36)
While mentioning one of the proofs of the truthfulness of the claim that Muhammad (sws) is the messenger of Allah, the book of Allah says:
O Muhammad, you have never read a book before this nor have you ever transcribed one with your right hand. Had you done either of these, the quibblers could suspect it. (29:48)
Which human faculty is the above verse appealing to? The fact of the matter is that the entire message of Islam is primarily addressed to human intellect. That’s why I stress it so much.
In Ahadith, it is mentioned that “...there are three people whose actions are not recorded: a lunatic till he is restored to reason, a sleeper till he awakes, and a boy till he reaches puberty.” (Abu Da’ud, No. 3823) In other words, we are responsible to follow the shari‘ah only because we have intellect. The one who doesn’t possess it is not even responsible for his actions.