Understanding one's own (and other people's) ever-surprising ability to disregard what is blatantly true is something of an obsession for me ATM. When you believe something defines you ("I am a Christian") it appears this cannot be questioned without putting at risk the whole idea of who you are.
As it transpires, the same regions of the brain light-up under MRI when confronted with an actual knife-wielding physical threat as when a statement contradicts closely held beliefs important to our identity:
The thing I would question is the conclusion. Are "who we are" and "what we believe" different things?