Most #dnd / fantasy #ttrpg settings out there seem to be vaguely based on Europe and European cultural assumptions.
However, most religious conflict in these settings seems to be based on conflicts between the followers of different gods. What I'd like to see more examples of is conflict between followers of the same god(s) who interpret their faiths differenty.
I mean, consider the conflict between Catholics and Lutherans in early modern Germany, which ultimately led to the Thirty Years's War - arguably the most traumatic war in the country's existence, eclipsing even the World Wars in many respects.
Such conflicts between different theological interpretations of the same faith have thus plenty of potential for conflict - and thus stories. However, you do need to make sure that the gods of your setting won't settle theological disputes directly...