Continuing on from the last post, as you may not have read the link, there exists a site called "Comic Book Characters Grouped by Religious Affiliation". Very dominational, but interesting. The assumptions are backed up by large essays referencing psychological studies and particular church characteristics. It appears that Batman, like the Hulk, is a lapsed Catholic (or Episcopalian), and Superman is probably Methodist.
I had no idea people spent their time in this way. check out the site here.