As far as I know, the Church was propagating the knowledge, literature, science and medicine. Also it was the first “organization” that in fact wanted to reject the slavery - but this fact is not well known, for obvious reasons. The truth is, the Church before VC2 was fighting the opression and spreading the equality around the world
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Its also the basis for our universities. And the monasteries kept the 'classical world' texts alive allowing for the renaissance at some point. The Middle Ages were a long period over a reasonably large territory and we don't actually know all that much; so it is easy to rant against the Church if you cherrypick times and places.
I'd say we have a lot of things to thank the Church for, and that is from someone with more Protestant sensibilities ;)