main argument
The case against LDS doctrine
LDS doctrine departs from Christianity at the level of God, Christ, salvation, scripture, and church authority. These are not side issues. They define the faith.
The God question comes first
Biblical Christianity begins with the one God of Israel. Deuteronomy, Isaiah, John, Paul, and Hebrews do not leave room for many true gods, exalted humans becoming gods, or a creator God working inside a family of divine beings.
LDS doctrine says the Father, Son, and Holy Ghost are separate beings, that the Father has an embodied form, and that exalted people may become gods. That is not the same doctrine stated in different vocabulary.
The Jesus question is not name recognition
Latter-day Saints confess Jesus as Savior and Redeemer. LDS doctrine then places Him inside a framework that changes what that confession means.
The New Testament presents the Son as the eternal Word through whom every created thing was made. LDS teaching places Jesus in a premortal family system with Heavenly Parents, spirit children, a chosen Savior role, and Lucifer as another spirit son who rebelled. That framework is not Nicene Christology.
The restoration claim is mutually exclusive
LDS doctrine does not say it is one ordinary branch of Christianity. It says the fullness of the gospel and priesthood authority were lost and restored through Joseph Smith.
If that is true, Christianity was fundamentally without the fullness for centuries. If Christianity is true, the restoration claim is false. The two systems cannot both be the same Christianity in the same sense.
Primary references
The argument rests on public Scripture, official LDS material, and Christian sources.
Are 'Mormons' Christian?
The Church of Jesus Christ of Latter-day Saints
Official essay acknowledging LDS rejection of post-New Testament creeds and distinct restoration claims.
Joseph Smith-History 1
The Church of Jesus Christ of Latter-day Saints
Canonical account where Joseph Smith is told to join none of the existing churches.
Restoration of the Church
The Church of Jesus Christ of Latter-day Saints
Official LDS source saying the fullness of the gospel was taken from the earth and restored through Joseph Smith.
Nicene Creed
United States Conference of Catholic Bishops
Representative text of the historic Nicene confession of one God, the Trinity, and the eternal deity of Christ.