What I've found is that people tend to get rather...
Attached... To their beliefs. The same often holds true of religion and other things besides, even something as simple and irrelevant as sports. A person gets attached like this because they have massive personal investment in the belief, and will often use any justification they can get their hands on to avoid being 'wrong' (or even just stick their hands in their ears and yell 'na na na na na na, I can't heaaar youu').
They will cling to their beliefs like glaze sticks to clay. If you try to calmly and logically explain where the flaws you find in their beliefs are, then you are '
THE ENEMY!' and everything you say henceforth is dismissed out of hand, because you are
personally insulting them, telling them they are terrible people and wrong about everything and should kill themselves... When you're just saying that, in this particular part of the belief, some improvement could be made to make it better.
Such people tend to end up boxing shadows, and react
violently to even the slightest notion that some part of their belief is, in some way, imperfect.
This tends to be their perception of 'the other', which can be anyone who doesn't share their exact beliefs and values, or even shares there values and is attempting to explain to them the flaws that those values have.
Yes, not all people are like this, it's simply and observation I've made. People can get like this in pretty much every scenario. It's quite... Unfortunate.