OED writes:
"act of misleading someone," c.1420; as a form of mental derangement, 1552. See delude. Technically, delusion is a belief that, though false, has been surrendered to and accepted by the whole mind as a truth; illusion is an impression that, though false, is entertained provisionally on the recommendation of the senses or the imagination, but awaits full acceptance and may not influence action.
I am not in love with either of the words. Religious belief could be provisional and awaiting full acceptance, or completely blind. Still, there is no illusion or no delusion if the belief is not proved wrong.
I do agree that certain parts of a religion can be erroneous, and believers deluded about them.
The act or process of deluding.
The state of being deluded.
A false belief or opinion: labored under the delusion that success was at hand.
Psychiatry A false belief strongly held in spite of invalidating evidence, especially as a symptom of mental illness: delusions of persecution.
None of these fit until something is proven false. For example, one could be deluded about the age of the earth, but Biblical inspiration is not in the same category.
Your definition may as well have been written by a religionist trying to make a point.
Religionist? No, it was a standard web definition.
I think Dawkins was right.
I think some people can't see the forest for the trees.
Edited by anastasia, : No reason given.