Why do Christians become Christians?

[Angrboda]

Conversion experiences like this have more to do with the nature of human psychology than the message being promoted.  The great tent revivals preached a far less 'friendly' message than contemporary revivals do, but the atmosphere was the same.  Hysteria and group think are not good reasons to adopt any belief.

Can you name some other examples that would illustrate your point that the message is not important? Hysteria and group think might come into play while one is at the meeting, but what accounts for days and years later when most are still Christians?

Once the switch is thrown, it tends to remain that way. That's just the way hysterical conversion works.