An Interesting Quote From the Koran

Those whom Allah wills to guide, He opens their breast to Islam; Those whom He wills to leave straying, - he makes their breast close and constricted, as if they had to climb up to the skies: thus does Allah lay abomination on those who refuse to believe.

The Qur’an: Surah 6:125 (Islam)

Now let us look at the quote with some corresponding jargon from protestant Christianity inserted (in parentheses).

Those whom Allah (in his plan) wills to guide (the elect), He opens their breast (regenerates, effectually calls) to Islam; Those whom He wills (in his predetermined plan) to leave straying (passes by), - he makes their breast close and constricted (reprobates), as if they had to climb up to the skies (makes salvation an impossibility): thus does Allah lay abomination (eternal damnation) on those who refuse to believe.

I think it is interesting how in the first part of the quote Allah is opening the breast and he "wills to guide" certain ones while he leaves others straying. Yet, in the last sentence he condemns those who "refuse to believe." This sounds contradictory. How can they refuse to believe Islam if they have been willed to be guided by Allah and have had their breast opened? On the other hand, what else could they do but "refuse to believe" if they have not been guided by Allah and have not had their breast opened? I suppose if I were to talk to a Muslim scholar about this he would be able to explain how it is not as contradictory as it sounds.