Based on limited research and talking to Mormon friends, here is the gist of Mormonism...
god was once a man who lived on a planet. He fulfilled the requirements of salvation so he was rewarded in the afterlife with a planet to rule of his own. We all have this potential to rule our own planet in the afterlife if we're good Mormons. Once a man is a god, he has celestial sex with his Mormon wife, who he spends eternity with ruling the planet, and each time they have sex a soul is birthed for their planet. Polygamy was encouraged because a god would spend eternity with many women, and thus populate his planet faster.
BAck to Yahweh according to Mormons...The first two souls born to god were Jesus and Lucifer. God called a council of the gods to determine his plan of salvation for his planet. He decided to have one of his sons sent to be a sacrifice. Lucifer volunteered, but Jesus was picked by God, and thus began Lucifer's rebellion. Jesus was sacrificed and with a combination of belief in Jesus and being spotlessly morally, one can gain salavation, too.
You should read Kingdom of the Cults by Walter Martin. It has some excellent info about Mormonism from a Christian point of view. It talks about how the cofounders of Mormonism denied the religion, saying it was a big hoax or something to that effect, but Joseph Smith chided and excommunicated them. There are also some interesting prophesies...Smith prophecied that there were people who lived on the moon and dressed like Quakers. When that was proved wrong, it was taken out of scriptures. Someone(Bringham young?) also prophecied that polgamy would never be made illegal in Utah. I suppose they chose statehood over prophesy fulfillment on that one.
OKay, well this is just off the top of my head. Again, I would suggest Martin's book, which gives references and such. I have no doubt that your missionary guests will deny most of this, so it may be good to brush up on the knowledge. They go through all kinds of training to expect and respond to anything you may say, so it would be good to at least know if what they are saying is actually backed by their scriptures or, moreover, by the Bible.
The religion has some wonderfuls aspects...missionary emphasis, morality, community, family, etc., but it is not christian according to the Bible, and thus by Christians (notably because of the polytheistic views).
Hope that helps.
Jake
edit: P.S. The part about becoming gods is preached less and less in the Mormon church as time goes by, and the church has reinterpretted the passages to not explicitly say this. A friend of mine raised in the Mormon church said he stopped hearing the hard core Mormon thoughts preached about 30 years ago. Since then the more "Christian" stuff has been preached. Also, he said there is much odd stuff that goes on in the temple, and anyone who goes in is sworn to secrecy. Hehe, I dunno exactly what he was talking about, but maybe it'd be worth doing some research?
[This message has been edited by Jake22, 08-20-2003]
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