"If we are children (of God)," wrote the apostle Paul to the Romans (8:17, New International Version), "then we are heirs — heirs of God and co-heirs with Christ."

"To him that overcometh," says the Savior to John the Revelator (3:21, King James Version), "will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in his throne. He that hath an ear, let him hear."

Mormonism has been harshly criticized because it takes those verses very literally. Late in his life, the Prophet Joseph Smith began to teach that humans, being children of God, can become like their Father. The doctrine is most famously expressed in the couplet of Lorenzo Snow: "As man is, God once was. As God is, man may become."

Joseph, critics often correctly say, was moving further and further away from mainstream Christendom.

But the doctrine of exaltation was revealed much earlier than the late, Nauvoo period of Joseph's life. Already in February 1832 — less than two years after the church's founding, nearly eight years before the Saints settled in Illinois — the Prophet learned that those in the celestial kingdom "are gods, even the sons of God" (Doctrine and Covenant 76:58). And it was implicit even before that, though perhaps unnoticed, in the Book of Mormon:

"And ye shall sit down," said Jesus to his Nephite disciples, "in the kingdom of my Father; yea, your joy shall be full, even as the Father hath given me fulness of joy; and ye shall be even as I am, and I am even as the Father; and the Father and I are one" (3 Nephi 28:10).

When we apply the transitive law of mathematics to this passage — according to which, if "a" equals "b" and "b" equals "c," it follows necessarily that "a" equals "c" — the conclusion is inescapable that, if humans can be like the exalted Christ, and if the exalted Christ is like the Father, then humans can be like the Father.

With this doctrine of exaltation or human deification, though, Joseph Smith wasn't actually moving away from Judeo-Christian tradition. He was returning to a forgotten strand of it.

For ancient Christians and Jews also had a doctrine of human deification, which scholars call "theosis."

As an early Jewish midrash or scriptural commentary expressed the belief, "The Holy One … will in the future call all of the pious by their names, and give them a cup of elixir of life in their hands so that they should live and endure forever. … (And He will also) reveal to all the pious in the world to come the Ineffable Name with which new heavens and a new earth can be created, so that all of them should be able to create new worlds."

The Christian saint Justin Martyr (d. A.D. 163) taught that "All men are deemed worthy of becoming gods, and of having power to become sons of the Highest."

St. Irenaeus of Lyons (d. A.D. 202) declared that "We have not been made gods from the beginning, but at first merely men, then at length gods. … (Jesus Christ) became what we are, that He might bring us to be even what He is Himself."

Clement of Alexandria (d. A.D. 215) believed that in the "future life" we will be among "gods … those who have become perfect … and become pure in heart … They are called by the appellation of gods, being destined to sit on thrones with the other gods that have been first put in their places by the Savior."

Tertullian, the first great Latin Christian author (d. A.D. 225), wrote that, through divine grace, the saved "shall be even gods."

Origen of Alexandria (d. A.D. 251) believed in "the Father as the one true God," but acknowledged "other beings besides the true God, who have become gods by having a share of God."

And the translator of the enormously influential Latin Vulgate Bible, St. Jerome (d. A.D. 419), insisted that "God made man for that purpose, that from men they may become gods. … They who cease to be mere men, abandon the ways of vice, and are become perfect, are gods and sons of the Most High."

Joseph Smith restored an authentically ancient Judeo-Christian doctrine. That's not a scandal. It's a miracle.

Daniel C. Peterson is a professor of Islamic studies and Arabic at BYU, where he also serves as editor in chief of the Middle Eastern Texts Initiative and as director of outreach for the Neal A. Maxwell Institute for Religious Scholarship. He is the founder of MormonScholarsTestify.org.