the basis of belief in Allah is upon 4:
   the natural inclination [Fitrah],
   the intellect [Aql],
   the legislation [Shari’ah], and
   the senses [Hawass].
it is a decision that can be made informed & critically, from evidence and rational reasoning.

as to how we know anything— we know through 3 sources:
   sound sense perception,
   reliable reporting, and
   logic & reasoning.
the only thing that is unknown through the former two, that can be apprehended through the latter (logic & reasoning) is the existence of the Necessary Being (the Creator) through that innate, necessary knowledge of our logical principles.
i.e. there are things that are unseen, and we innately incline to knowing the only thing we can innately know among the unseen, the Creator.

the more certainty that we have in the Creator Most High, the more certainty we will have in His having all of the attributes of perfection, and none of the attributes of imperfection: the more certainty in His Perfect Justice.
when we see this life, we know it is full of injustice and people die in that state. our living appears to result in our dying with some injustices experienced, and with our living is the accountability for those injustices. 
therefore since this Perfection necessitates Justice—and our in our living is accountability to Him: this means we will live again with a period of full accountability attaining full justices. 

so—it must be that we live again to be accountable to His Justice. 
that is known the Last Day, the Day of Judgment, the Day of Resurrection, the Day of Recompense, etc—wherein all souls that have lived and died will be resurrected and held to account in His Perfect Justice.

the more certainty that we have in that Day — the more we will want to meet Him, being pleasing to Him, not angering Him or deserving His Wrath or having gone astray.
that is something we need constant help with, and so we are regularly in need of connecting to Him for that success and guidance from Him.




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Acceptance of the prophethood of Muhammad ﷺ is not a matter of chance or probability; rather, it requires understanding and conviction. The evidence and arguments presented in support of his ﷺ prophethood are not uncertain or ambiguous, but rather clear and compelling: he ﷺ could not have been a liar, nor could he ﷺ have been deceived by Satan, and he ﷺ certainly was not a madman. 
The Qur'an, as the primary source of Islamic teachings, presents a clear and coherent message that appeals to our natural constitution, based on reason, evidence, and moral principles. It challenges us to reflect on our own beliefs and actions, urges us to seek guidance from the Creator, and reminds us to remember His signs in the creation.
This acceptance is not a decision made on an uncertain outcome; it is a rational decision based on the supporting evidence and reasoning. 
Faith, in Islam, is far from being a blind belief without rationality; rather, its reality entails sincere affirmation of that rationality and basis from which belief springs forth.