Unpopular Opinion

It's a fairly common tactic of evangelical religious groups to send young people out to proselytize; they say that they're called to spread the religion to the whole world, and that the proselytizing is to save people by converting them. The tactics that the young people are taught are often antagonistic. An extreme example is the Westboro Baptist Church, but all evangelical religions use similar tactics. Unsurprisingly, very few people convert. The true purpose of antagonistic proselytizing is to reinforce in/out group status; the youth are rejected by outside people, while being praised by people within their own group. That reinforces their feelings of comfort and safety within their group, and makes it more difficult for them to leave. Leaving the safety of the group means that they're severing their most intimate social connections, and that cost is too high for most people.

This was my experience as a Mormon; this has been the experience of many Mormons, and of all people that have left high-demand evangelical religions.

IF they really cared about getting more people to join their religion, they would be opening and welcoming to people, even people that were antagonistic to them. When you think about it from a PR standpoint, it should be clear that acting antagonistically towards people that simply don't believe the same things--not people that are being antagonistic themselves--works counter to the purpose of persuasion.