I actually love it when Christians/Mormons come knocking at our door trying to convert us. We invite them in for tea and a little talk in which WE tell them about our religion and they tell us about their's. In the end, they always end up getting so impressed with Islam and take our phone number before they leave so they can call and talk again sometime. We once had two Mormon girls in their early twenties come to talk to us about their religion. They wanted us to convert, but well, we talked to them about Islam and they were so impressed and took our phone number. We gave them both a Quran translation copy. A few months later one of the girls came back and asked us for our mosque's phone number because she read the Quran and did lots of research on Islam and decided it was the religion for her. She converted the next week. So it turned out that she came to convert us, but we converted her instead.