When a Christian and a Latter-day Saint use the word "God," they are not talking about the same being.

That is not a polemical claim. It is a theological one — and it is important to understand it clearly before any conversation about faith with a Mormon friend, neighbor, or family member. The differences are not peripheral. They go to the very foundation of who God is.

The most concise summary of LDS theology about God comes from Lorenzo Snow, the fifth president of the LDS church: "As man is, God once was; as God is, man may become."

This statement captures two things at once. First, that God was not always God — he was once a mortal man who progressed to divinity through obedience and exaltation. Second, that human beings have the potential to become gods themselves. Both ideas are foreign to historic Christianity. Both are central to LDS theology.

Joseph Smith taught this explicitly in the King Follett discourse, delivered in 1844 shortly before his death. He said: "God himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens." This is not a fringe teaching. It is foundational LDS doctrine.

In LDS theology, God the Father has a body of flesh and bones as tangible as man's. This is stated directly in Doctrine and Covenants 130:22, one of the LDS scriptures beyond the Bible.

This is a direct departure from historic Christian theology, which holds that God is spirit — infinite, incorporeal, and not composed of matter. Jesus said in John 4:24, "God is spirit, and those who worship him must worship in spirit and truth." The God of the Bible does not have a physical body. The God of Mormonism does.

Historic Christianity teaches that God is eternal, self-existent, and unchanging. He has always been God. There was never a time when he was not God. He did not become God; he simply is God — the uncreated ground of all being.

LDS theology teaches the opposite. God progressed to his current divine status. He was once a mortal, living on another world, who through faithfulness and obedience was exalted to godhood. This means that in LDS theology, God is a contingent being — he exists within a larger framework of eternal laws and progression that even he is subject to.

This is not a minor difference in emphasis. It is a different kind of God entirely.

Because LDS theology teaches that humans can become gods, it follows that there are many gods — an infinite chain of exalted beings who have progressed through mortality to divinity. Our Heavenly Father is the God of this world, but he is not the only god in existence.

This is a form of polytheism, though LDS members often resist that label. They typically say they worship only one God — the God of this world — even while affirming that other gods exist. The technical term sometimes used is "henotheism": the worship of one god among many.

Historic Christianity is strictly monotheistic. There is one God, and there is no other. Isaiah 44:6 records God saying: "I am the first and I am the last; besides me there is no god." Isaiah 45:5: "I am the Lord, and there is no other; besides me there is no God." These are not statements about which god deserves worship. They are statements about how many gods exist.

LDS theology explicitly rejects the doctrine of the Trinity. God the Father, Jesus Christ, and the Holy Ghost are three separate, distinct beings — not one God in three persons. They are united in purpose and will, but they are not one in being or substance.

The LDS church teaches that the Nicene Creed — the foundational statement of Trinitarian theology — was a corruption of the original Christian faith, introduced by Greek philosophy after the apostles died. The "restoration" Joseph Smith claimed to bring was, in part, a restoration of a non-Trinitarian God.

Historic Christianity holds that the Trinity is not a philosophical imposition but a faithful reading of Scripture. The Father, Son, and Spirit are each fully God, and yet there is one God. This is not a contradiction to be explained away; it is a mystery to be confessed.

Understanding the LDS view of God is not about winning an argument. It is about knowing what you actually believe and being able to explain it honestly.

When a Mormon says "I believe in God," they mean something different than you do. When they say "God loves you," the God they are describing has a physical body, was once a mortal man, and exists within a larger cosmos of gods and eternal laws. That is not the God of the Bible.

The most productive conversations about this topic tend to start with questions, not declarations. "What do you believe God is like?" or "Do you think God has always been God?" opens a conversation. Quoting Isaiah 44 and walking through it together is more fruitful than announcing that Mormonism is wrong.

The goal is honest engagement — not hostility, not capitulation, but the kind of clear and respectful conversation that takes both people seriously.

The Christian Field Guide covers the nature of God, the Trinity, and the key differences between LDS theology and historic Christianity in detail. Start with The Companion — it's free — or go deeper with The Field Guide, which includes a full section on Mormonism organized by doctrine.

Understanding what someone believes about God is the beginning of every real theological conversation. Start there.