Answer by Ernie Jones:
I would recommend that you read a slim volume called "Influence" by Robert Cialdini.
If you believe something that everyone else believes, it doesn't take much (if any) psychological resources to continue believing that thing.
On the other hand, if you hold a belief which is significant to your identity, such as the religion of your country and culture and family and childhood, and that belief is attacked, especially if it is continually attacked and attacked by the dominant culture, then in order to retain your sense of identity, you have to actively devote psychological resources to shoring up that belief against the assault, and as a result you become increasingly entrenched in your belief.
This phenomenon is commonly observed in end-times cults, for example, when the predicted end time passes without a world-shattering cataclysm. You'd think that members of the cult would abandon their belief, but this is not in fact what happens. Rather, the group casts about for an explanation until they find one which fits their world view, and then something very interesting happens. Such groups typically are very closed, very focused on the fact that they know the truth and others don't and outsiders don't have any place. But once their predictions fail, and they've come up with a justification, they tend to become evangelical, opening up their doors and obsessively attempting to convert others to the cult, because the more people they can convert, the more comfortable they are in continuing to believe something for which they have sacrificed everything — because in most cases they've severed all ties with friends and family and even given away all their possessions in anticipation of the event.
What you're describing is the same process.
The more you're exposed to people "mocking, hating and insulting" your religious beliefs, which like all religious beliefs are based on faith rather than logic and evidence and therefore cannot be rationally defended, the more you're forced to choose between accepting the criticism — which would mean turning your back on your family, your culture, and even your own personal identity forged in childhood — or digging in deeper.
Most people choose to dig in deeper.