What do you call someone who belives in many religions?

It sounds like they've taken a Frankensteinian approach to religion.

I've seen these "Coexist" bumper stickers on cars made of different religious symbols which suggests that they're all the same and all espouse the same ideas and beliefs. However when you examine them closely they actually are quite different from each other and even contradict each other at key points.

I think the person you're referring to is wanting to find the best in each faith and may be searching.

Pantheist.

Fake, nonsensical.

Christian God = Jealous, vengeful, top rule is to not worship any other gods. Not exactly compatible with "believing in multiple religions."

People who say they believe in multiple religions don't take any of them seriously, or they are so illogical that they can't be taken seriously.

Spiritual

I think they'd have to be pretty well educated. The bible is who book of nonsense, then you have to remember all the hindu gods' names, and know how to pronounce the aztec gods. It'd be quite the intellectual challenge.

Celebrating a holiday doesn't necessarily mean you follow the religion. For example, giving gifts at Christmas doesn't mean you follow part of Christianity. It means you give gifts around Dec 25. Likewise, being a vegan doesn't make you a part of any religion, etc.

There's no term for what you're describing.

Spiritually eclectic.

there is an artist where i live who believes in multiple religions, they just call him a hybrid believer or an omnist. But i think omnist is correct.

They are spiritual but not religious. A religion is something specific.

If you're truly interested in an answer, please read Ephesians 4:14