The most obvious of these ideas is the concept of "holy war," an idea that had previously been foreign to Christian thought. Prior to the Crusades, the church had used its influence to discourage armed conflict. Forced conversions may not have been unheard of before Christianity's first contact with Islam, but they weren't as common as they became.
Another concept that's less obviously a product of Islamic thought is that of submission. It's important to note that there is a distinction between obedience and submission; submission goes much further than obedience and leads to a fatalistic mindset within which freedom exists only as something to be surrendered in favor of being saved from eternal torment.
While some Christian traditions have a looser definition of submission than others, most agree that God has a plan for every step that a person takes through life, and that this perfect plan can be fully discerned from the unchanging, universal commands that the Bible exists to provide us. Only in "liberal" circles does the Holy Spirit's guidance serve any real purpose other than to steer us (or to help us steer others) back to that set of all-encompassing rules.
Islam means submission (to God's will). Just as mystics negate themselves to give place to God, so Muslims have the same religious orientation. Not just obedience but submission is involved. At a first glance this seems to be in full conformity with the biblical revelation. We know how important a role is played in current piety by the formula mektoub, it was written. We have to submit to the sovereign, preexistent, eternal, and immutable will of God. All history, all the events of history, all the things that come to pass in each individual life have already been decreed and fixed in advance and written by God.Ellul's arguments here tie into the concept of Open Theism, in which the future is unwritten, even by God. Many Christians still view Open Theism as heresy, even though it's arguably more biblical than the idea of a God who transcends time. If everything that will ever happen has already been witnessed by God, then how can free will be anything other than an illusion? And without free will, how can we ever truly love God or those around us?
In reality this is the very reverse of what we are told about the biblical God, who opens up freedom for us, who lets us make our own history, who goes with us on the more or less unheard-of adventures that we concoct. This God is not "providence" (which is never a biblical word). He is never a determinative cause or an irreducible conductor of events.
The biblical God is he who unceasingly reestablishes our human liberty when we keep falling into bondage. He unceasingly enters into dialogue with us, but only so as to warn us about what is good, to set us on guard, to associate us with his will; never to force us. Here again the tendency to believe in a God who because he is omnipotent is also omniscient (which presupposes that everything is already said) was already present in Christian thinking when it was invaded by certain elements in Greek thought. Yet at first the themes of salvation and love were always dominant. I believe that it was the strictness of Muslim piety that really led Christians along this path.
If we make God's omnipotence dominant over his love and autonomy, his transcendence over the incarnation and liberation, then we think of his omniscience as an inscribing of history and events in a nexus of events that has already been established, that is unchangeable and immutable, and that all takes place at a stroke. Then we do not have to enter into a dialogue with God, or into a monologue that, like Job's, demands a response from God, but simply have to submit to the unchanging and, in a true sense, inhuman will of God.
The whole Bible, whether in the Old Testament or the Gospels, tells us that there is no such thing as destiny or fate. All this is replaced by love, and hence the joyful freedom that the first Christians experienced. But gradually, and insidiously, fate stages a comeback. (pgs. 107-108)
From now on destiny and divine omniscience are conjoined. Believers can live in perfect peace because they know that everything was written in advance and they can change nothing. The very formula "It was written" could come only from a religion of the book. Yet the Hebrew Bible and the Gospels never use such a formula.One can see these concepts at work in the ex-gay movement, where the only options presented to anyone with a homosexual orientation are change or death. Once again, free will exists only in the form of a single binary choice: one either submits fully to one's predetermined fate, or spends eternity being endlessly punished for choosing incorrectly. If that's truly the freedom that the Apostle Paul speaks of, then perhaps we're not taking enough of our cues from Islam.
Thanks to it, the idea of predestination that was already haunting philosophical and Christian thinking received confirmation, forcibly established itself, and came to include double predestination (in Calvin), which, whether we want it or not, transforms the biblical God into destiny, Ananke, etc. And this derives from Muslim thinking. For it is not just historical events that were written in advance; it is also eternal salvation (or rejection). Ultimately this conviction came to dominate a good part of Christendom, and paganism rejoins it with its belief in the god of fate. (pg. 108)