Balduran
Terrarian
This reminds me. A lot of people hate religions so it's not that an unpopular religion.I worship the moon (named after it too) because it gives me hope, makes me happy, and I look to it when I have issues. It makes me feel better and helps me, which is what I think religion is really about.
What is unpopular though, is having a strong dislike of modern paganism/Wiccans. Almost all that I've met IRL were overzealous and pushy about their beliefs.