Mormonism and polygamy

I think one of the most compelling beliefs of mormons was cronicled in the video called 'Lifting the Veil of Polygamy'.
The practice of Polygamy is a belief system that has been taken out of the mainstream LDS church today. Mostly the biggest influence of the faith comes from Joseph Smith and what he did. Something most people may not know is that many of the practices that Mormons do that Christians do not do are not in the Book of the Mormon and contradict their other scriptures. There are two other books that the LDS use as scripture the Peral of Great Price and Doctrine and Covenants which were written by Joseph Smith. Back to polygamy, Joseph Smith had a revelation of Polygamy which is in the Doctrine and Covenants. One of the concepst stated is that plural wives is needed to attain Godhood. They believe that one day they become Gods of their own planet and will populate the planet with their spirit children.
So polygamy becomes essential for salvation. For the woman it becomes very difficult to leave. In one of the verses in Doctrine and Covents it says that if Emma who was Joseph's wife does not allow him to marry other woman she will be dammed to hell. The woman in polygamy become afraid to leave despite how bad it can be sharing your husband with other wives. They sometimes leave and then go back to it because they believe they are going to hell if they do not follow this teaching. So it can be a long road for them to get away from the group. One woman who you can see the love of Christ radiate from her face spoke of it as that every day is a crap shoot and nothing was ever going to be good enough. Their is no grace for them in their beliefs only try and try. She talked about hiding her feelings and deny that living this way caused her pain. She said they are never sure they have a home in heave. I think that is one of the main beliefs to grasp about the LDS.
They belive salvation is worked toward that is not grace alone. They want to attain Deity. We live by the spirit not the flesh. Romans 3:21 "But now apart from the Law the righteousness of God has been manifested, being witnessed by the Law and the Prophets," Romans 8:1 "Therefore there is now no condemnation for those who are in Christ Jesus" They dont know all of what Jesus has done for them.

I hope that makes sense I know im not an amazing writer. I could type for hours and not finish the many things about the LDS Church.