Michael had the priesthood and participated in the creation. Before entering the garden, Adam was given (eternally married) to Eve. After they were driven from the garden, Adam was given the Aaronic and Melchizedek priesthood. Did Adam (and Eve)lose the priesthood secondary to the fall? If not then why was the priesthood restored (as per endowment)? If they did lose the priesthood when did they lose it? We know that Adam had the higher priesthood at the end of his life when he called all of the righteous for blessings.
Joseph Smith spoke about Adam’s pre-mortal priesthood:
“The Priesthood was first given to Adam; he obtained the First Presidency, and held the keys of it from generation to generation. He obtained it in the Creation, before the world was formed, as in Genesis 1:26, 27, 28. He had dominion given him over every living creature. He is Michael the Archangel, spoken of in the Scriptures. … [He] held keys first on earth, and then in heaven” (Teachings of the Prophet Joseph Smith 157).
Adam received the priesthood during creation, but did not hold the keys until he was on earth. I read this as being a form of a preparatory ordination, or foreordination. Alma 13:3 talks about high priests “being called and prepared from the foundation of the world according to the foreknowledge of God, on account of their exceeding faith and good works”. This pattern even continues in mortality. When I was 12, I received the priesthood, but I wasn’t ordained a priest until I was 16. My understanding of the Endowment leads me to believe that, prior anointings notwithstanding, yet another priestly ordination awaits me if I am faithful.
I remind you that the Endowment drama is highly symbolic, and as such, can only be properly understood by the Spirit. I would not put too much weight in Adam literally receiving first the Aaronic then the Melchizedek Priesthoods, especially since “all priesthood is Melchizedek” and scripturally there was no need for a lesser priesthood until Israel rebelled.