I would say that religion is a spectrum like anything else.

What I call ‘normal’ devout people are just trying to live their lives and be decent people. They don’t have any sort of agenda, but may have a relatively shallow understanding of their religion (not much beyond “God says ‘be a good person’”), rituals and scriptures. My grandma is like this - she isn’t very educated and uses her religion for personal comfort.

Then you get the apologists, cult leaders, babas, nationalists and so on and so forth.

I think you can be devout without necessarily having an understanding of your religion, and be ok, but it’s the fervent religious people who go around trying to convert everyone via apologetics, police other people’s behaviour etc who are in really choppy waters, ethically speaking.

You can get laymen who are pretty knowledgeable, but religion is generally so wide-ranging that unless you’re studying it at a historical level, it’s pretty hard to understand in-depth.