(1) Many parents want their children to believe as THEY do. They have their religious beliefs or rather inculcations that were passed generationally which were accepted without question. Many family members believed in such religious inculcations to keep the family peace/uphold familial tradition so to speak. They also mindlessly follow familial religious concepts in order to be accepted by family members. Those who question such concepts are viewed as suspects. They are deemed as strange, even the odd one out in the family. The family will assert every effort to get the "errant" family member in line. It is deemed quite unthinkable for these parents that a family member would question familial religious tradition. It is even worse for such parents for family members to disavow/not believe in that religion anymore. Such parents oftentimes wonder where they went wrong instead of accepting that there will be family members who go on a quite different path than they did. Such questions & going on a different path in the eyes of these parents threaten, even disrupt the familial fabric. These parents simply refuse to believe that their children are individuals but instead see them as replicas of themselves.
(2) Besides family members, there are people who believe that THEIR religious beliefs, paths, & perspectives are the ONLY, LEGITIMATE ones & that other beliefs, paths, & perspectives are not only wrong & erroneous but ....EVIL. They will try to proselytize others to their way of thinking by using guilt mechanisms to get others "to see that light." These people are of the school that if others do not have their religious beliefs, paths, & perspectives, they are "sinners, even damned" unless they "repent."
In conclusion, such parents & people are unevolved & immature. These parents & people refuse to see that each person is where h/she is supposed to be regarding his/her ethical, moral, religious, &/or spiritual path. No one can/should believe alike. Each person is on his/her particular stage of belief whatever that may be. Besides that, each person has his/her individual choice as to what h/she believes. Evolved, enlightened, & mature people realize that each person believes differently, respects, & even encourages such.