In Mormon scriptures, the Church says yes, Adam and Michael are the same personages. In fact, they went so far as to publish and canonize Smith’s revelation about it!
Their website shows Smith received a revelation in Harmony, PA, in August 1830.
D&C 27:11; “And also with Michael, or Adam, the father of all, the prince of all, the ancient of days.”
You can also find the same info in their temple endowment ceremonies. The full text is available on our site at Temple Endowment Ceremony, Day 1, The Creation.
However, the Church will also tell you Adam and Michael aren’t the same at all! You’ll also see how they mentioned the name, ‘ancient of days’, who is neither Adam, nor Michael. The Ancient of Days is Jesus!
Compounding the problem, Smith wrote about another vision he had and recorded it in his diary six years later on Jan 21, 1836. In this vision, he said that he “saw father Adam and Abraham and Michael…”, naming each as a separate personage. You can read it in full at the Joseph Smith Papers site – Visions, 21 January 1836 [D&C 137]
This vision was later added to D&C 137, but the reference to Michael is completely gone.
D&C 137:5; “I saw Father Adam and Abraham; and my father and my mother; my brother Alvin, that has long since slept.”
So now we’re back to square one, and left still asking the same question…
Are Adam and Michael the same person, or not?