When I was working the night shift, I felt kinda lonely, so when the Mormon missionaries knocked on my door, I figured hey, why not? I invited them in.
They were quite young, very polite, but not very knowledgeable. I told them right up front, of course, that I did not believe. They kept coming back with more and more material, but we never really got anywhere, because I felt it would be unfair for me to get into a deep, religious debate with someone so young and naive.
They eventually stopped coming by, and I'm not sure if this was because of any specific incident, or just because they gave up -- but there was an embarrassing moment, when I burst out laughing at one of their promotional tapes (which were extremely well produced) misspelled "Jesus Christ" -- I think they left out the "h" or something. I didn't intend to mock or ridicule them, but it seemed so absurd that such a high quality production would make such a bad mistake, so when I saw it, I just burst out laughing and yelled, "Oh dude, they misspelled Jesus Christ!"
At the same time, by some odd coincidence, a Jehovah's Witness dropped by. I talked with him by the door for a while -- he didn't want to come inside. He was perfectly polite and respectful, and by no means pushy (the JWs used to be very pushy in the past, with the all-out "foot in the door" thing, but they don't do that at all anymore -- although this reputation still sticks with them), but he far more eager about getting into a serious debate. Besides, he was a middle-aged guy, and seemed far more knowledgeable than the Mormon kids.
After a short debate, he lauded my knowledge of the Bible, and that he'd return with some more documentation, and another person, to get into the debate further. The next week, he showed up with an elderly fellow who had a huge stack of books and photocopies, and we went at it. I love a good debate, and although it's okay if it gets heated, I still think you should keep a cool head. The old man didn't. When his arguments didn't hold out, he got so angry, he screamed at me, and pounded his fist on my dining room table.
I didn't take any particular personal offence at this, but clearly -- to be a guest in someone's home, and act like that, that's pretty bad. They didn't return after that.
Couple of months ago, I was visiting a friend, when a couple of Mormons dropped by. He hates this kinda stuff, and apparently has problems getting rid of them. Well, we'd had a few brews, so I was tad inebriated, and since I'd seen them coming, when my buddy opened the door, I yelled "OH, MORMONS -- AWESOME!" and at that point they got extremely nervous, and were quite easy to get rid off. Shoot, I woulda liked to have invited them in.