So while this interview is pretty crap--I mean the interview asks all sorts of leading questions, which you're not supposed to do in interviews. Still there are some fine sections and insights. Read it all, but for now here is a section on aesthetics and conversion:
Was it the beauty of the Pietà that struck you?
Yes — and the context. This is God, I thought. This really is God. You must remember that one of the big things when we look at traditional Islam is the heresy — in their opinion — of equating the mortal Jesus with God. And if there is ever an obstacle that a Muslim convert has to contend with, intellectually and emotionally, more than anything else, that is it. At that moment, in front of the Pietà, I realized, through sheer emotion, that the truth of our religion is so simple and so direct.
PS: A recent issue of Global Missiology also has an article on aesthetics and conversion, for those interested in the rather esoteric topic.