Why do Christians become Christians?

[Mister Agenda]

It works hand-in-glove with your original argument from "appeal" which I addressed earlier. On what grounds would you exclude the appealing draw of security, belonging and community for reasons some become or remain Christian?

I'm sure that is part of the appeal. However there are other ways (including other religions) to get these things from. So why does Christianity seem to resonate well with people (judging by its continuous past and projected numerical growth)? I maintain it is the message I outlined in the OP.

I maintain that it is the proselytization, which also neatly accounts for why Islam is growing (and projected to grow) even faster. If it was the message, other messages wouldn't do as well given similar effort.