When is a Religious Belief Delusional?

[BrianSoddingBoru4]

- Unquestionable certainty.
- Resistance to scrutiny.
- Contrary to what is demonstrably false.

That said, the devil is in the details. My initial question to atheists is this. How do you justify the claim that all religious beliefs, or those most commonly held, satisfy the above criteria (or others you may propose that are not listed)?

I have had conversations with theists (real life as well as online) in which I was told, in so many words, 'I don't care what your evidence is - God is real to me.'  This strikes me as satisfying the three criteria list: If a person avows to hold to a belief irrespective of evidence presented, that particular person is delusional in their religious belief.

Let's take, by way of example, possibly the common core belief of all varieties of Christianity, and well as more than a few other religions: God loves us and wants us to be happy. 

Unquestionable Certainty  I don't think it is unfair to say that people who hold this belief hold it with unquestionable certainty.  If fact, it they doubted that God loved them, or were to even admit that possibility that God didn't love them, they would likely abandon their religion, or even abandon religion in toto.

Resistance to Scrutiny  No one likes having their core beliefs questioned, that's pretty plain. But if you asked someone to justify how they know God loves them, they'll almost always give an answer that shows they haven't examined this belief closely ('I feel His love in my heart' or 'God loves me because God IS love'), or they'll get upset with you for even asking the question (I've had this experience more than once).
Contrary To What Is Demonstrably False  I think you may have misworded this one.  I'm going to assume you meant 'Contrary to what is demonstrably true'.  A lot of claimed miracles (weeping/bleeding statues, spontaneous stigmata, the blood of St Januarius, etc) have been demonstrated to be deliberate frauds, or to at least have more prosaic explanation that Divine intervention. Yet people still believe in them.

Boru