I think that a lot of Atheists oversimplify religion. (NB: I'm Atheist myself.)
"True" and "false" only apply to statements about reality (epistemic). And sure, religion has a lot of them: "God exists", "if you fornicate you'll go to Hell", "the world was created in seven days" etc. I think that most of them are false.
However a religion isn't just its epistemic statements. It's also morals, practices/rituals, and a community. Those things cannot be true or false, because they are not statements about reality. You need another ground to refer to them, as "good" vs. "bad" (deontic).
At the risk of upsetting people, most if not all religions. They can't all be right.
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