If the findings of historical criticism are right, then some kinds of theological claims are certainly to be judged as inadequate and wrong-headed. I… - Bart D. Ehrman

One of the most amazing and perplexing features of mainstream Christianity is that seminarians who learn the historical-critical method in their Bible classes appear to forget all about it when it comes time for them to be pastors. They are taught critical approaches to Scripture, they learn about the discrepancies and contradictions, they discover all sorts of historical errors and mistakes, they come to realize that it is difficult to know whether Moses existed or what Jesus actually said and did, they find that there are other books that were at one time considered canonical but that ultimately did not become part of Scripture (for example, other Gospels and Apocalypses), they come to recognize that a good number of the books of the Bible are pseudonymous (for example, written in the name of an apostle by someone else), that in fact we don't have the original copies of any of the biblical books but only copies made centuries later, all of which have been altered. They learn all this, and yet when they enter church ministry they appear to put it back on the shelf.

The only way to make sense of a text is to read it, and the only way to read it is by putting it in other words, and the only way to put it in other words is by having other words to put it into, and the only way you have other words to put it into is that you have a life, and the only way to have a life is by being filled with desires, longings, needs, wants, beliefs, perspectives, worldviews, opinions, likes, dislikes— and all the other things that make human beings human. And so to read a text is, necessarily, to change a text.

Christianity may well have succeeded even if Constantine had not converted.