Christianity stresses Free Will. Humanity is free to choose good or evil and suffer the consequences.
Islam denies Free Will and turns all that happens over to the capricious desires of Allah.
'And a soul will not die but with the permission of Allah; the term is fixed; and whoever desires the reward of this world, I shall give him of it, and whoever desires the reward of the hereafter I shall give him of it; and I will reward the grateful.' - Koran, Surah III: 145
You might as well blow yourself up because you have no free-will and you'll die when Allah wants you to, and if you die blowing yourself up, it must be because Allah wants you to, so why feel guilty about it?
"O you who believe! take care of your souls; he who errs cannot hurt you when you are on the right way; to Allah is your return, of all (of you), so He will inform you of what you did." - Koran, Surah V: 105
This one is kind of interesting. If the enemy wins it is because you were not faithful enough.
"For his sake there are angels following one another, before him and behind him, who guard him by Allah's commandment; surely Allah does not change the condition of a people until they change their own condition; and when Allah intends evil to a people, their is no averting it, and besides Him they have no protector." - Koran, Surah XIII: 41
I call this one the catch-22 passage. I suppose Mohammed meant to say that God helps those who helps themselves, but remembered it wrong. Instead you have a recipe for fatalism.
"And those before them did indeed make plans, but all planning is Allah's; He knows what every soul earns...." - Koran, Surah XIII: 42
More fatalism. In the end, it's all up to Allah.
"Allah causes the unjust [unbelievers] to go astray, and Allah does what He pleases." - Koran, Surah XIV: 4,5
More catch-22 from Allah. No free-will to choose to believe or not believe because Allah decides who will or will not, and then punishes you for what is essentially his decision.
"Surely Allah will defend those who believe; surely Allah does not love any who is unfaithful, ungrateful." - Koran, Surah XXII: 19-23
So, if an American Army full of unbelievers beats a Muslim Army, what does that mean? I'd like to hear an Imam explain this one. Good thing they don't allow tap shoes in mosques.
"Nay! Those who are unjust follow their low desires without any knowledge; so who can guide him whom Allah makes err?" - Koran, Surah XXX: 29
There's that catch-22 again. Allah makes us err, and then sends us to hell because we did. That's I'd call unjust.
All very interesting, but it then begs the question: the Byzantine Christians did not want to become Muslims. They were worshipping God in the Christian way, and many were quite devout.
The Muslims invaded, thinking the way they do, and the victory went, in province after province, to the Muslims. There were a million different instances of chance and good fortune that could have cut either way, but God chose to let the Muslims win. One example of this, in a slightly later period: on the Third Crusade, a truly enormous Western Army was descending on Outremer to assist it in beating off Saladin. The Christian army was in three parts, with the largest part being the army of Fredrick Barbarossa, Emperor of Germany. With that Army, the Crusaders were virtually guaranteed a victory, and thereby would have restored most of the Middle East to Christendom, and preserved Christianity.
But Barbarossa had a freak accident crossing a river in Asia Minor, and drowned. This was not a matter of act of free will; it was an act of God...an act of God that caused the Imperial Army to melt away and abandon the cause. Coeur de Lion and Philippe Auguste were both still able to reduce Acre and to hold their own against Saladin, but there was no prospect of breaking Saladin and Muslim power after that. Now, I look at that and I see a divine choice, an act of God that determined the outcome of the Third Crusade, and thereby doomed Christianity in most of the Levant.
And I wonder, theologically, why God let the Muslims utterly triumph over the Christians.
The Christians weren't just defeated, but the Christian religion and way of worship was permanently deleted from those lands.
Inaccurate.
Islam believes in both human free will, which makes men accountable for their deeds, and in the ultimate control of Allah.
This view is actually very similar to that of Christianity, especially those branches such as Calvinism which stress predestination while still claiming to believe in free will. All these groups get around the obvious contradictions in very similar ways, which to an objective observer look very much like sophistry. :)
Your quotations from the Koran can be balanced by many other quotes showing that man is a free agent and responsible for his actions. If taken out of context, similar quotations from the Bible would "prove" that Christians believe God's omniscience does not allow for human free will.
Probably that they must kill many more infidels to re-earn Allah's favor.