Why do theists keep trying to convert people even though they are wrong?

I've had Christians(?) try to convert me off and on for all my 19 years. I'm currently debating with two Muslims over whether or not you can number-fudge, conclusion jump, misdirect, mistranslate, and ignore every fact which goes against what you're saying to turn a false statement into a true one. I've also had Mormons repeatedly lie and twist facts around to me to get me to become a good tithe-paying Utahan. The only theist group around here that hasn't tried any **** was that Reform synagogue I went to.