To answer that question, we must look to the Bible for the answer, since it repeatedly warns God’s people against altering divine revelation to establish a new religion. From the Law of Moses to the final chapter of Revelation, Scripture presents itself as a message from God that must not be modified by human authority. Three passages are especially significant:
Deuteronomy 4:2 declares:
“You shall not add to the word which I command you, nor take from it, that you may keep the commandments of the Lord your God which I command you.”
Galatians 1:8–9 states:
“But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.”
Revelation 22:18–19 warns:
“If anyone adds to these things, God will add to him the plagues that are written in this book; and if anyone takes away from the words of the book of this prophecy, God shall take away his part from the Book of Life.”
These passages establish a clear biblical principle: God’s revelation is not to be supplemented, altered, or replaced. Any religious movement claiming new doctrines, new scriptures, or a new gospel must therefore be tested against the teachings already revealed in Scripture.
One movement that raises this question and must be tested against the teachings of the Bible is Mormonism, officially known as The Church of Jesus Christ of Latter-day Saints (LDS).
Additional Scriptures
Traditional Christianity recognizes the sixty-six books of the Bible as the inspired Word of God. Mormonism, however, accepts additional writings as scripture, including The Book of Mormon, Doctrine and Covenants, and The Pearl of Great Price.
According to LDS teaching, these books contain revelations given after the completion of the biblical canon. Joseph Smith, the founder of Mormonism, claimed to have received new revelations from God and angelic messengers.
This claim immediately raises a biblical concern. Deuteronomy forbids adding to God’s revealed word, and Revelation closes with a severe warning against doing so. While LDS defenders argue that these passages refer only to specific books rather than to the entire Bible, traditional Christianity has historically viewed them as expressing a broader principle: God has already provided the authoritative revelation necessary for faith and salvation.
The acceptance of additional scriptures therefore places Mormonism in tension with the biblical warnings against adding to God’s revealed truth.
Another Gospel
The strongest challenge to Mormonism comes from Galatians 1:8–9.
Paul warns believers that even if an angel from heaven were to preach a different gospel, that message must be rejected.
This warning is significant because Joseph Smith claimed that an angel named Moroni appeared to him and revealed the location of golden plates from which The Book of Mormon was translated. Thus the origin story of Mormonism involves precisely the kind of angelic revelation Paul warns Christians to test.
The issue is not whether an angel appeared, but whether the message agrees with the gospel already revealed through Christ and His apostles.
Traditional Christianity teaches that salvation is by God’s grace through faith in Jesus Christ.
Ephesians 2:8–9 states:
“For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.”
Mormon doctrine affirms grace but also incorporates temple ordinances, priesthood authority, and various covenant requirements into its understanding of exaltation and eternal progression. As a result, many evangelical Christians conclude that Mormonism presents a gospel fundamentally different from the apostolic message found in the New Testament.
Because Paul pronounces a curse upon any alternative gospel, this difference is viewed by traditional Christians as a serious doctrinal departure.
Authority and Continuing Revelation
A major distinction that cannot be dismissed or be subject to compromise is the source of authority for Christianity.
Traditional Christianity teaches that Scripture is the final written authority for doctrine.
Mormonism teaches continuing revelation through living prophets. New revelations can clarify, expand, or modify previous teachings.
This concept creates an authority structure that extends beyond the Bible alone. From a traditional Protestant perspective, such continuing revelation conflicts with the biblical pattern of preserving and guarding the apostolic faith once delivered to the saints (Jude 3).
The Nature of God
Perhaps the most significant difference between Mormonism and historic Christianity concerns the nature of God.
The Bible teaches that there is only one eternal God.
Deuteronomy 6:4 declares:
“Hear, O Israel: The Lord our God, the Lord is one!”
Isaiah 43:10 records God saying:
“Before Me there was no God formed, nor shall there be after Me.”
Historic Christianity has therefore taught that God is eternally God and that no other gods exist.
Mormonism teaches that God the Father possesses a glorified physical body and that He progressed to godhood. LDS teaching has also historically taught that faithful believers may eventually become exalted beings in like manner.
This concept differs sharply from biblical monotheism as traditionally understood from Sola Scriptura. Christians see the Bible presenting a clear distinction between the Creator and His creatures, whereas Mormon theology introduces a concept of eternal progression that goes beyond the clear teachings of Scripture.
The Person of Christ
Traditional Christianity teaches that Jesus Christ is the eternal Son of God who possesses the same divine essence as the Father and the Holy Spirit, the Trinity of three distinct Persons who are the LORD, the one God of Deuteronomy 6:4.
Mormonism differs from this understanding in a fundamental way. While LDS doctrine affirms the deity of Jesus Christ, it does not teach that the Father, Son, and Holy Spirit share one divine essence. Instead, they are understood as distinct beings united in purpose and will. Consequently, traditional Christianity views Mormon theology as departing from the biblical doctrine that there is only one eternal God.
The central difference is not whether Jesus is divine, but whether the Father, Son, and Holy Spirit are one God or three distinct divine beings. Historic Christianity affirms the first position; Mormonism teaches the second. separate beings in a way that departs from the traditional doctrine of the Trinity.
While both Christians and Mormons affirm that Jesus is the Savior, the underlying understanding of God’s nature differs substantially.
Conclusion
The biblical passages in Deuteronomy 4:2, Galatians 1:8–9, and Revelation 22:18–19 establish a consistent warning against altering God’s revelation or proclaiming a different gospel.
When Mormonism is examined in light of these passages, several significant differences emerge. Mormonism accepts additional scriptures beyond the Bible, traces its origins to angelic revelations that proclaimed a new gospel, teaches doctrines concerning God and humanity that differ from historic Christian belief, and recognizes continuing prophetic revelation outside the biblical canon. For example, the president of the LDS Church is regarded as a prophet who possesses authority to receive revelation for the church and to speak on behalf of God.
For these reasons, traditional Christianity has generally concluded that Mormonism is not simply another Christian denomination but a separate religious system that departs from essential biblical doctrines. Many Christian apologists and theologians have therefore classified Mormonism as a Christian cult because it employs Christian terminology while redefining key biblical doctrines concerning God, Christ, salvation, and revelation.
Christians should treat Latter-day Saints with kindness, respect, and genuine love, and recognize that in modern America, people are free to choose their personal belief system. However, they should also carefully compare LDS teachings with Scripture and heed the apostolic command to test every doctrine against the revelation God has already given. When that is done honestly, Mormons cannot be accepted as Christian in the biblical definition of the word.
The issue ultimately comes down to authority. If the Bible alone is the final and sufficient revelation of God, then every later teaching must be measured by it. Where subsequent revelations contradict or go beyond the teachings of Scripture, the Bible’s own warnings require believers to remain faithful to the gospel once delivered to the saints.
