So what happened in the beginning? Yes, that beginning. In the beginning, God created the heavens and the earth and all that is in them. He also created the Tree of the Knowledge of Good and Evil. He told the Earth's first two inhabitants not to eat of this tree or they will surely die. This is where the big lie comes in. The serpent, that nasty talking snake convinced the woman that God had lied to them. That they would not surely die. He said that once they ate of the tree, that they would be as God. Now that's a lie. You know the rest.
So let's flash forward a bit to the 1800's when Joseph Smith, the founder of Mormonism, starts his new religion. What does he tell the folks that find him interesting? He tells them the big lie. The original one. He or one of his subordinates said, and Mormons today believe, that God (you know, God the Father, creator of everything) was once a man just like us. Somehow he was able to live a good life and earn his very own planet. Yes, his planet is the planet Earth. The one we all know and love. The lie goes on to say that we too, if we are good Mormons, can someday earn our own planet where, you guessed it, we can become as God. Yes, you too can have your very own planet to literally Lord over. How nice. They even have their very own bible.
Does this resemble anything close to orthodox Christianity? Do not be deceived. They are not Christian in any sense of the word.