If you ask me why people accept Islam, I can give you two answers:
(a) one, a very simple human one.
(b) The other, a most complex, unfathomable, divine one.
From a human point of view, the process and outcome of conversion from this or that “Religion” to Islam, and, more specifically, from Non-Islam and Pre-Islam (Jaahiliyyat) to Islam, is the composite function of a billion (times Infinity) variables, some known, most unknown or exogenous, each with its own specific value and error component and distribution, acting in concert.
And, from that perspective, the entire result being entirely predictable or explainable, within a certain margin of error, provided we have at our disposal all the theoretical models, and all the methodological tools and instrumentations required for the purpose of figuring out these things.
And we also have all the applicable specific variable values.
I am calling this human equation simple because there is a way, and there is a hope, that somehow and sometime, maybe, we can solve this puzzle.
The divine answer, on the other hand, may appear simple when stated in our daily language. But it is unknowable in both theory and practice, as it transcends the limits of human knowledge and the powers of human understanding in every way and at every level.
And as it defies the capacities of human instrumentation to (define and to) measure.
For, it means knowing God in all his attributes. And -- Allahu Akbar and Subhanallah, who can ever make such a claim?
And it means understanding the calculus of God’s mercy and dispensation, and of God's Grace with regard to his creation.
Simply stated, it does not lie in human power to know or understand God and the internal dynamics of the way God does things.
Or even the external dynamics, for that matter, that may appear to meet the human eye, and to register on the human radar, and to be amenable to human instrumentation and scalability and measurement.
Our very humanity is defined in terms of our general inability to comprehend God and the ways in which he dispenses his grace and mercy to his creation.
Read the Aayat Karimah:
Wa Laa Yuheetoona Bi-Shai-im Min 'Ilmihi.
“Not an iota of his infinite knowledge are they about to grasp or comprehend!”
Meaning, when it comes to God, we as human beings draw a complete blank.