Muslim scholars in the dark ages preserved Greek texts ("western" thought) and advanced mathematics.

A whopper of a myth there. What really happened was that all the ancient texts rotted in the humid north but were preserved in the dry Muslim-conquered areas. And the so-called Muslim scholars were in reality Non-Muslims living in dhimmitude (third-class subjects) in the vast jihad-conquered areas.

You don't have to spend much time studying the unchangeable flawless Last Testament to see why scholarship and Muslim don't go together very well. You can see in the Acts of the Apostles the embodiment of the principle of arguing ones's case rather than fighting it; and conversely Saint M's principle of winning one's arguments via violence against dissenters, the notion repeated stated that military victory comes to the "righteous"

The Old Testament is the Jews' ancient history book, and the whole point of Christianity is that it changes from and supercedes it. The principles expounded by JC & Co did not explicitly at any point challenge the Romans' legal principles (because they would have been very quickly executed if they had--which is why Christ's reply "Render to Caesar what is Caesar's and to God what is God's" was such a clever reply to his enemies' trick question). But those Christian principles of loving one's neighbour as oneself etc most certainly are incompatible with any form of slavery other than one that makes the concept meaningless.
You will search for that in the Qur'an in vain. The Q spends a lot of time discussing the making and taking and keeping of underdogs of various sorts.

No it was not a church-induced Dark Ages, it was caused by the collapse of militaristic Rome and the pagan barbarian gangs' Volkerwanderung. In the midst of a vast reversion to wood-age darkness, the lights were kept shining only in the refuges of the Church. And only out of that church everything about the modern civilisation arose. See Tonybee a study of history.