I think she's equating religious to church-going, or perhaps observant. The most basic tenet of religion is belief in a deity, so she's way off the mark, in my opinion.

You said the right word last that matters... "Nice".

Maybe she's saying you need to believe in the God but she doesn't care if you believe the dogma?

So if you don't have to be religious to be a Christian, then don't do anything that the religious would do, like:

Believing in a god
Praying
Going to church
Farting in the pews

She is just giving you another lame excuse that believers tell themselves to justify their hateful or weird actions. "Oh, I'm not like them, I'm not religious."