That's what you said originally.
Following pure logic (I hope we understand each other here) absense of evidence is not a proof. Therefore you cannot say "false" here.
Now to the "irrelevant" bit here.
If anyting is not directly applicable/not observable/doesn't fit current scientific dogma/"unreasonable", it is not absolute. Religion is not relevant if it is put in the context that you put it in. The problem is you don't try to switch context.
Bingo. So you can't know, and ultimately assume. Hence my ramblings about various contexts.
With that said religion is "irrelevant in the context of modern science and empirical thought", but not just just plain "irrelevant". You can think as rational as you want, but it never hurts to keep an open mind and know that you may, in fact, be wrong.