Last week I invited some Mormon missionaries to my sociology of religion class. We were studying rational choice theory of crime, and I had the missionaries talk for 15 minutes on why the class should become Mormons. Afterwards, the students asked questions and wrote an essay applying rational choice theory to Mormonism.
Overall, it went really well. The poor missionaries, two young women, were exceedingly nervous, but I greatly appreciated their courage in talking with the 200 students.
My students were appropriately gracious in interacting with the missionaries, but there were two times when a lot of jaws dropped.
At one point, a student asked why women have shorter missions than men (18 months vs. 24 months), and a missionary sort of shrugged and said that "they want us to get married young." Pretty sure that's not an idea heard a lot here.
Later, the missionaries were asked about LDS practices, and they mentioned no alcohol, drugs, premarital sex, and then--gasp--no coffee. From the looks on the students faces, the speakers might as well have pulled their faces off to reveal alien heads underneath... What a shock!