Joseph Fielding Smith notes that, while Adam holds the keys, he does so under the authority of Jesus, who is greater than Adam.
Joseph Fielding Smith, Conference Report (April 1942): 26
Now, some members of the Church have wondered just what was meant by the words of the Prophet, that we without our dead could not be made perfect. Will not a man who keeps the commandments of the Lord, who is faithful and true so far as he himself is concerned, receive perfection? Yes, provided his worthy dead also receive the same privileges, because there must be a family organization, a family unit, and each generation must be linked to the chain that goes before in order to bring perfection in family organization. Thus eventually we will be one large family with Adam at the head, Michael, the archangel, presiding over his posterity, according to that which is written in the Scriptures. This he will do under the direction of the Holy One of Israel, for so it is revealed in the Scriptures:
That you may come up unto the crown prepared for you and be made rulers over many kingdoms, saith the Lord God, the Holy One of Zion, who hath established the foundations of Adam-ondi-Ahman; who hath appointed Michael your prince, and established his feet, and set him upon high, and given unto him the keys of salvation under the counsel and direction of the Holy One, who is without beginning of days or end of life.
I think we ought to get that clearly in our minds because there are those who are trying to stir up trouble among the Latter-day Saints today by teaching doctrines that are not in accordance with the revelations of the Lord, and maintaining that Authorities of the Church who have gone before taught doctrines which they did not teach. So we must have it understood clearly that while Adam will preside over his posterity as Michael, the prince, and as he will hold the keys of salvation, as he does, all' of that will be under the direction of Jesus Christ, the Holy One of Israel, for Christ is greater than Adam.