Many religions continually bring up either real or perceived persecutions. By increasing the perceived price paid for a belief system it is less likely the believer will renounce their faith. It is well said here:
“Procedures, customs, and traditions are often specifically established for the purposes of creating psychological commitment. Consider fraternity initiations, military boot camps, political rallies, protest marches, and demonstrations. When we make our vows, beliefs, statements, or endeavors public, we feel bound to them. We can back out on commitments and claims we’ve made public, but we will pay a psychological and emotional price. What’s more, the more public we made those commitments, the greater the emotional price tag will be.”
By the time most believers are in their twenties they have given so much emotionally, fiscally, and temporally to religion that it is very, very difficult for them to turn away from the fraud. Fundamentalists of all stripes engage in similar behaviors. Islam has the haj, all of the hours spent in worship, the differences in lifestyle that sets them apart, and focusing on anything that can be slightly perceived as persecution. Many benign comments and publications are viewed as anti-Islamic. Judaism has the same things with the haj being replaced by Bar and Bat Mitzvahs, religious giving, etc. Many valid comments and criticisms are labeled as antisemitic in a knee jerk reaction. It results in the believers feeling that they have given so much and suffered immensely for their various faiths. Inoculation with cognitive dissonance that extreme often results in people being able to defend the ludicrous for a lifetime. The bad thing is that every time they defend their bogus beliefs their propensity to engage in confirmation bias, denial of disconfirming evidence, and the need to protect their self-image by defending their chosen stance also increases. It is a self-perpetuating quagmire that few escape.
Our chemical computers that we call brains are just wired that way. The unscrupulous are all too willing to take advantage of this human weakness.