Have you tried asking Them what they wish you to call Them?
I don't believe in a 'them', I believe in an omnipresent divine. The reason I don't use the word them, is basically because I don't see the divine as a person. To refer to it as a person would be limiting.
The whole point of creating subdivisions (in my case) is to create a representation of an aspect of an otherwise indefinable thing. Depending on which aspect I want to relate to at the time, I will use a name that represents it appropriately.
I think that the divine has a way of signalling whether the names are appropriate, anyway. There have been some names I've considered, that have sounded good to me, but, for some reason, didn't feel right. I believe that most of the 'gut feelings' we get, are actually just the divine giving us hints.
Thanks for the suggestion though.