I think it's interesting that some (only some) singers of traditional material select so as to avoid songs with a spiritual/religious theme. Now I understand that if you don't believe in something, you might not want to sing about it and be mistakenly thought that you do. But it's also true that Christianity in particular is a huge part in the formation of European culture, and secular (i.e. not in church) songs of a religious nature are numerous.

This is one reason I like Maddy Prior's repertoire -- she doesn't shy away from songs with a religious theme. I have no idea whether she is a believer or not, and I certainly wouldn't conclude that from her choice of material. Really it's none of my business, is it? But I'm glad she includes those songs in her setlists. They're part of the heritage of folk song in English.

The material is there, and gingerly singing around it denies part of our heritage.