One of the major teachings of the LDS church is that we humans are all begotten children of God, just like Jesus, which is why they refer to him literally as our firstborn brother. The New Testament Greek term for “beget” is gennaÅ, which is used for fathers (and also mothers: Luke 1:13, 57; Luke 23:29; John 16:21; Galatians 4:24) when they “produce” a child. When anyone “begets” a child, the children share the human nature of the parents. So when God “begets” a Son (as the New Testament describes it), this means that this Son shares God’s divine nature.
It has always been the teaching of the historic Christian church that Jesus is the only begotten Son of God (John 1:14). He is the only one that shares both God’s nature and Mary’s. To be precise, he was “begotten” by the Holy Ghost (Matthew 1:18-20; Luke 1:35), not a Heavenly Father with an exalted human body, as taught by the LDS church.
By contrast, the LDS prophet Brigham Young declares that Jesus was “not begotten by the Holy Ghost” (Journal of Discourses 1:51), and taught that we humans are all “the king of kings and lord of lords in embryo” (Journal of Discourses 10:233). The LDS concept of us all being begotten children of God is obviously different from our historic Christian understanding, and we’re not exaggerating the difference.
Please note: the Nicene Creed did not invent, but simply unpacked the New Testament teaching that Father, Son, and Holy Ghost share the same nature. And yet, the canonical Bible makes it equally clear that there is only one God. Isaiah 45:22: “I am God, and there is no other.” Deuteronomy 4:39: “The Lord is God in heaven above and on the earth beneath: there is no other.” Joel 2:27: “I, the Lord, am your God, and there is no other.” So even though the Nicene Creed’s term homoousias (“one in substance”) is not found in the Bible, just put the puzzle parts together, and the classic Christian Trinity is the logical product.
A side issue is whether these three personalities are “one God” or simply “one in purpose.” The Bible’s clear teaching that there is only one God should inform all other discussion on this issue. Jesus speaks of being one with his followers, or them being one with each other, but to say that Jesus means the same thing when he says “I and the Father are one” in John 10:30 is to torture his meaning. The Jewish bystanders understood that; that’s why they pick up stones to throw at him. They do so “for blasphemy, because you, being a man, make yourself God.” (John 10:34) Even the Book of Mormon states that Father, Son, and Holy Ghost are not just “one in purpose,” but “one God” (Mormon 7:7, 2 Nephi 31:21, Alma 11:44, 3 Nephi 11:27, 36), a teaching which Joseph Smith discarded by 1838.
The LDS take John 17:21-22 as evidence that Father and Son are not literally one. Their “gods unlimited” approach allows them to do that. But for historic Christians who prioritize the literal oneness of God, it is Jesus’ comparison of our unity to the unity of the triune God that we take non-literally.
Now, a common belief out there is that we are all children of God in a non-divine sense, as if we are part of God’s family and therefore beneficiaries of his love and other family privileges. The New Testament teaches, however, that those who place their faith in Christ (not the whole human race) are children of God, not automatically by birth, but by adoption.
Galatians 4:4-5 says that God sent his Son to redeem us, “so that we might receive adoption” (huiothesia). Ephesians 1:4-5 says that God “predestinated us unto adoption (same Greek word) of children by Jesus Christ to himself.” Adoption was an extremely familiar institution in the Greco-Roman world. The power of the image comes from the fact that a child who was completely unrelated by DNA gained all privileges of a begotten child of the adopting father.
That’s us. We are children of God, not by sharing the same nature, not even simply by being born into the human race, but because God has given us a brand-new status that we did nothing to deserve, nor were we entitled to it by birth or DNA. Romans 8:17 says that God has given us the Spirit of “adoption,” which makes us heirs of God and fellow-heirs of Christ, which we were not previously.
Jesus has no spirit brothers. We were adopted! If we are adopted children of God, that means that we did not begin our lives as God’s children, in either an LDS “begotten” sense or a figurative “human family” sense. And that adopted status that we have received comes through placing our faith in what Jesus has done to take away our sins and put us right with God.