A unique doctrine that was taught for decades in the early church is that of Adam-God. In essence, the doctrine teaches that Adam was once a mortal man who became resurrected and exalted. From another planet, he came as Michael to form Earth. Adam brought Eve, one of his wives, with him to Earth, where they became mortal by eating the forbidden fruit in the Garden of Eden. After bearing mortal children and establishing the human race, Adam and Eve returned to their heavenly thrones where Adam serves as God and is the Heavenly Father of humankind. Later, Adam returned to the Earth to the ancient prophets, and to become the literal father of Jesus.

From the Journal of Discourses, v. 1, p. 51 Brigham Young:

Now hear it, O inhabitants of the earth, Jew and Gentile, Saint and sinner! When our father Adam came into the garden of Eden, he came into it with a celestial body, and brought Eve, one of his wives, with him. He helped to make and organize this world. He is Michael, the Archangel, the Ancient of Days! about whom holy men have written and spoken—He is our Father and our God, and the only God with whom we have to do. Every man upon the earth, professing Christians or non-professing, must hear it, and will know it sooner or later.

Crash Course:
Journal of Discourses, v. 1, p. 51
Adam God Doctrine – Mormon Think
The Adam God Coverup – Rational Faith
Adam-God Doctrine – Wikipedia