Missionaries are called by the head of a church to share the wisdom they have acquired. They knock, but they are not suppose to share if you are not willing to listen. They are ascetic in a way. They have no home in this period of their life. They are only the tools of God.
In times long ago, the same habits could be seen in Hinduism and Buddhism. Yet, with most other religions, there is serious physical and artistic proof of their beliefs. Propaganda of the highest nature. Though, these forms of propaganda are there to enlighten and teach.
I have noticed recently, that LDS missionaries are becoming more pushy. I believe it is wrong to push your belief on others. I wish I could be in the position to apologize. Furthermore, shows like South Park and whatnot, do not clearly lay out the true grounds of the religion, and South Park is made to parody and poke fun, using popular beliefs, which are incorrect in many cases (one such belief is that of polygamy).
I have heard that Mary was compared to Shiva. Yes. This is interesting.
Shiva is the God of creation and destruction. He is both the mother and the father. In this way, he has both God and Mary's position. Ancient Egypt's Osiris and Isis are also compared to Mother Mary and Christ.