Aristotle was a giant in christian theology, probably bigger than both Aquinas and Ockham. Much of high scholasticism was based entirely on implementing Aristotelean philosophy in a christian context and continuity. Also Plato played a very major role in christian theology, mostly through St Augustine and other neoplatonists.

Aristotle was actually to a large extent "forgotten" in Europe for a long time after the fall of western Rome but was kept alive by eastern roman and most importantly arabian philosophers like Avicenna. This arab tradition of Aristotle then traveled back to Europe in large part through then islamic Spain, and when Aristotle returned he returned in force.

The fact is that much of aristotelean (and platonic) thought is very easy to apply to christian theology, "the immovable mover" for instance, which is a part of the explanation of why his thought wasn't just thrown out as heresy. You have to also keep in mind that a large part of scholasticism (and especially Ockham) was the notion of Rationalism as uncompromisingly good in the eyes of god, which is why Aristotle (and many other antique philosophers) was regarded as a forgivable pagan. Aristotle was of course in some form a heretic - but he was still not condemned to damnation.

An example of how aristotelean thought played a part in christian theology was the Vallodolid debate where christian theologians argued whether or not the natives of the newly found new world were sons of god. Both sides of the debate argued based on aristotelean principles and even used quotes directly from Aristotle to prove their points since his thought held such an enormous authority.

Source: Piltz, Anders. Medeltidens lärda värld (1978)

I'm sorry I don't have any english source.