Mormon founder Joseph Smith and Mormon apostle James E. Talmage ("As man is, God once was; as God is, man may be." by LDS Apostle James E. Talmage, Articles of Faith, Ch.24, p.430-p.431) mistakenly believed that "just like man, God was once a tangible body of flesh and blood; then just like God, man may become God." On the contrary, biblical Christians believe that God is a spirit (see John 4:24), so those who worship God must worship him in the Spirit and in truth. The God we worship is the creator of the universe (see Genesis 1:1). God said in Isaiah 46:9: “Remember the former things, those of long ago; I am God, and there is no other; I am God, and there is none like me.”
Regarding sin and salvation, Smith added: “People will be punished for their sins, and people can only be saved by grace.” Unfortunately, they also believe that everyone can only be saved through the Church of Jesus Christ of the Latter-days Saints, which is Mormonism. The Mormons mistakenly believe that salvation is only possible through the Mormon priesthood and continuous revelations from God. But Ephesians 2:8 clearly says: “For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God.” Therefore, our salvation is entirely the grace of God through the redemption that came by Christ Jesus. God presented Christ as a sacrifice of atonement on the cross for all who believe in him. (See Romans 3:24-26).
The believers of the Church of Jesus Christ of Latter-days Saints proclaim that their Bibles such as the Book of Mormon and the doctrines and covenants of Mormonism have not been fully written. They are waiting for God's revelations that may appear at any time, and their scriptures and writings can then be added and revised accordingly. Paradoxically, if Mormons’ truths and commandments that they need to obey now might be affected by future revelations, how can they discern temporal doctrines from the permanent, and be able to choose and follow the eternal truth? This may also cause one’s decision of observing or not observing the truth and commandments to be based on personal needs and preferences. Then what truth is left to speak of? People will be hopelessly at lost. 2 Peter 1:3 says: "His divine power has given us everything we need for a godly life through our knowledge of him who called us by his own glory and goodness.” Indeed, brothers and sisters, the words and truths inspired by the God who called us are as stated in Deuteronomy 4:2: "Do not add to what I command you and do not subtract from it, but keep the commands of the Lord your God that I give you.”
May we fear God and be wise to obey Jehovah’s commands. Amen!