My naive questions

[Thumpalumpacus]

So how do you surmount the issue?

Look at the religions that you reasonably can and make a choice.

By analogy, there could be a better spouse for you than the person you're engaged to. You don't need to date every single eligible potential mate in order to make a decision. By that logic you'd never get married.

And what of the divorce rate?

You don't need to research every single career in the world in order to select one. By that logic you'd never have a career.

And what of folks who study one thing at school, and decide they hate the career only after entering the workforce?

There are many choices we make on incomplete information, and as noted they can be decisions which are vital to our happiness. At some point, you just pull the trigger and commit.

And that's a great point, so long as the possibility of error is acknowledged. Without that, it's a bit disingenuous -- not that you're engaging in that, that's not my point.