Your argument states "Science says that untestable claims about reality are unreliable" and not "Science says that making things up is not a reliable way to determine truth". Your argument also states "Religion says that certain untestable claims about reality are reliable" and not "Religion says that making things up is a reliable way to determine truth". There is a difference between the reliability of finding the truth by making up a claim and the reliability of the claim itself.
Your argument (from what I can tell as it is written) is not about the reliability of making up a claim but about the reliability of a claim itself. Even if your argument were referring to the reliability of making up a claim, I don't know of any religion that says or concludes that making up claims is reliable. Even if one did, that wouldn't lend itself to making the blanket statement "Religion says ...".
> "reliability of a claim" means the probability that the claim is true, based on what you know. The fact that some of the claims might be true does not mean that the probability of any particular claim being true is high.
Defining, conversely, the "unreliability of a claim" as the probability that the claim is false, your argument becomes the following:
> 1) Science says that untestable claims about reality have a probability of being false.
> 2) Religion says that certain untestable claims about reality have a probability of being true.
> 3) Therefore, religion's claims as to the probability of being true of some claims about reality contradicts science's claims as to the probability of being true of those claims.
Given that your argument makes no reference to what is more or less probable, no contradiction has been established (pending whether you mean unreliable to mean less likely and reliable to mean more likely (but then you'd need to establish how those probabilities were derived)). I don't want to put words in your mouth, so you may want to rephrase your argument because I doubt this is what you meant given that it does not establish your point.
> It's not reliable _for_ anything, it is simply likely to be a correct description of reality.
You can't/don't rely on scientific claims "_for_" anything? As in, the claims of science are not reliable for things like putting satellites into orbit or pursuing further truths, they are just likely a correct description of reality?
>> Assuming your saying "It is not warranted" because the claim "God exists" is not falsifiable, how has it been shown that the claim "God exists" is not a falsifiable claim?
> What would you accept as falsification of the claim of the existence of the god that you believe in?
You're shifting the burden of proof. I have at least five independent criterion, but you don't need to know them. Not having something to accept as falsification for the claim "water only boils at 100°C or greater (under 1 atm)" doesn't mean that there can't be one. So unless you have some solid demonstration of your claim, because lack of evidence doesn't seal the deal, then you have no convincing basis for claiming "'God exists' is not a falsifiable claim".
> All you are really saying here is "What if reality isn't real?" ...
Hahaha, what?? Not at all! I'm saying that, given what seems to be your want of disregarding all non-falsifiable claims as "indistinguishable from stuff someone just made up", you'd also be disregarding the claim "our senses our reliable" as "indistinguishable from stuff someone just made up" because that claim is not falsifiable in principle (it being non-falsifiable something we seem to agree on since we think it is self-evident).
If you think the claim "our senses are reliable" is falsifiable, then YOU would be the one likely to assert the question "What if reality isn't real?".
> And yes, I am aware that I am skipping a lot of stuff. ...
Thank you for mentioning it. I couldn't tell if stuff was being missed or ignored. It can be easy to miss things in walls of text.
> ... so I think we are better off concentrating on that for now ...
Sure, I've done more skimming myself.