There are many differences between Mormonism and Christianity. Much of Mormonism comes from the Bible . . . but much of it doesn’t.
God saved you by his grace when you believed. And you can’t take
credit for this; it is a gift from God. Salvation is not a reward for the
good things we have done, so none of us can boast about it.
Most of us like to earn our way. Even to heaven. The Mormon faith embraces that ambition. Founder Joseph Smith laid down human requirements for getting to heaven.
But the Bible says we cannot earn our way to heaven—no matter how hard we try. However, because He loves us, God did provide a way for us to be forgiven and saved. Christ died on the cross to pay the price for our sins. His sacrifice was perfect and complete. He earned salvation for us. We can be forgiven, saved from the penalty of our sins, only by faith in Christ and what He did for us—not by doing good works.
This is the main issue that divides the Mormon faith from Christianity. But God loves Mormons. Christ died for their sins, and He invites them to receive his gift of salvation.