I simply want to convince you to entertain the possibility that people might profess to believe in God for reasons other than indoctrination or stupidity.

Why do you think any convincing is necessary?

arguing against religious beliefs on logical grounds [...] spirituality is not about logic. It's about subjective experiences [...]

Religious beliefs and subjective experiences are quite separate things, at least in principle. If someone simply says "I went to church and had this amazing experience", I don't think even the strawmanniest Spockiest stereotypical rationalist would have much quarrel with that. But here in the real world, actual religious people tend not just to say "I had this amazing experience" but to go further and say "I believe in God, the Father Almighty, creator of all things seen and unseen, and in one Lord Jesus Christ", or "Hear, O Israel: the Lord is our God, the Lord is one", or whatever.

(They not infrequently go further still and say "you must do X and not do Y, because God says so", or attempt to get laws made requiring X and forbidding Y, or in very extreme cases blow things up in an attempt to intimidate people into doing X rather than Y, and that sort of behaviour tends to be what provokes the louder sort of unbeliever, rather than mere professions of belief. But let's ignore that for now.)

So, consider someone who has these amazing experiences and reacts to them by (not merely appreciating the experiences, but) declaring that those experiences give him special insight into the nature of reality, and professing belief in a particular religion's doctrines. There are (crudely) three possibilities.

• Perhaps he means what he says at something like face value: he actually intends to make claims about how the actual world actually is.
  • In this case, arguing against those claims isn't a matter of misunderstanding What Spirituality Is About; our hypothetical religious person really is making (alleged) factual claims which may be right or wrong, supported or undermined by the evidence, etc., and argument is an appropriate response (at least in some contexts).
• Or perhaps he doesn't mean to make actual factual claims; when he says "I believe in one holy, catholic and apostolic church" he really means "I had an experience where I felt like I was one with the universe"; when he says "Muhammad is the messenger of God" he really means "something ineffably indescribable happened to me".
  • In this case, indeed arguing against the claims he makes may be a mistake. But it might be perfectly reasonable to argue against using those claims to express those experiences. Because, really, take a look at typical religious professions of faith, theological writings, etc.; do they look to you like good ways of expressing ineffable overwhelming religious experiences? They don't to me.
• Or, finally, perhaps he actually doesn't make those claims at all; or, at most, he makes them when required to make them by some ritual he participates in, and otherwise refrains.
  • In this case, finally, I do agree: the usual sort of religious argument may be entirely irrelevant to this person. But it seems to me that (1) most people who profess religious belief are not like this person, and (2) most people who engage in argument against religious beliefs are, most of the time, not doing so in discussion with someone like this.

In this sense, God is everywhere.

In this sense, we are all Spartacus. In this sense, the Singularity is here. In this sense, I am the walrus.