Why do you believe?

[pocaracas]

Here's my point: Naturalism (atheism and materialism, essentially) entails that prayer never works--and when it "does", it's only coincidence.

So if any prayer ever works, you have evidence that disproves atheism.

I think you wanted to finish with "If all prayers work, you have evidence that disproves atheism." Otherwise, you fall into the coincidence well.