Pluralism vs Monism
I think the fact that there exists religious pluralism kind of discredits every religion itself. Think about it, if you had been born and raised elsewhere, you would have had different religious beliefs. If our founding belief and faith seems so arbitrary it makes question if you can really know wether your religious beliefs are true.
Look at the following argument for instance:
1. Your religious beliefs were instilled in you from childhood.
2. Therefore, your religious beliefs were not formed
sensitively, or
safely, or are at best true by accident.
3. Therefore, you don’t really know that your religious beliefs are true.
A belief is formed insensitively when the belief is false but you still choose to believe it. It is unsafely when you could have just as easily believed a false fact with the same reasoning. And it is unjust when despite the evidence you prefer to live in the lie.
Peoples strong beliefs can be defined by cognitive biases like
Confirmation Bias; tendency to search for , interpret and confirm ones's preconception,
Endowment Effect; tendency of people to hold onto their value than adopt new ones despite the evidence or
Sunk Cost Fallacy; placin the disutility of giving up ones faith higher than the utility of acquiring a new one.