Many Christian apologists, perhaps most prominently Dinesh D'Souza, argue that even secular people should be grateful to Christianity for the heritage of its dominant position in Europe during, and for long after, the Middle Ages. Indeed, I have often heard, or seen, secular thinkers such as Jurgen Habermas accepting this general point, even though I find it, myself, to be (to say the least) implausible.
Of course, there's a trivial sense in which we can all feel glad for everything that happened before we were, as individuals, conceived, since Who Gets Conceived And Born (or which sperm cells fertilise which oocytes and produce which zygotes) is ultra-sensitive to all prior events. Moreover, the existence of all the good things that we have in the world today has been highly sensitive to the actual course of history that led to them (but the same applies to many bad things in the world). Is there some sense, more substantial than these, in which the world - particularly Europe - is better off as a result of the centuries-long hegemony of Christianity?
That really depends on what the realistic alternatives were. We could imagine a worst-case scenario in which barbarian warriors dominated the Dark Ages with no influence from Christianity or from classical learning. All traditions of philosophy and science might have been lost, and perhaps we (or our equivalents) might have ended up as worshippers of Wotan or Thor.
Conversely, we might imagine scenarios in which classical learning survived and thrived in Europe through what we know as the Dark Ages.
It would be foolish to imagine that the actual course of history was the very worst it could plausibly been, so, insofar as Christianity may have prevented some even worse outcomes, perhaps we should be glad and grateful. But does that mean that the Dark Ages, as actually experienced, were an improvement on pre-Christian classical paganism? Were they a ferment of learning and innovation, misnamed by Enlightenment ingrates who failed to appreciate what was achieved under the aegis of the Church during the centuries after the fall of Rome?
Andrew Bernstein is one commentator who thinks not. See this ferocious critique of Christianity's contribution to European civilisation. I must say that Bernstein's occasional genuflections to Ayn Rand, a third-rate thinker at best, and the provenance of the article in a Randian journal, don't add to the author's credibility. But it's easy to ignore the references to Rand, on which nothing in the argument depends, and to replace the brief discussions of Randian epistemology with something more plausible (some kind of post-Popper philosophy of science, perhaps). Once that's done, the article is interesting and (perhaps) persuasive. Have a look and let me know what you think.