High priests after the order of the Melchizedek Priesthood have a right to officiate in their own standing, under the direction of the presidency, in administering spiritual things, and also in the office of an elder, priest (of the Levitical order), teacher, deacon, and member. (D&C 107: 10)
I ran across an illuminating quote concerning this verse. The quote was from John Taylor:
“ALL PRIESTHOOD FUNCTIONS UNDER DIRECTION IN CHURCH CAPACITY.—There is another question associated with this matter. Because a man is a high priest, is he an apostle? No. Because a man is a high priest, is he the president of a stake, or the counselor to the president of a stake? No. Because he is a high priest, is he a bishop? No, not by any means. And so on, in all the various offices. The high priesthood holds the authority to administer in these ordinances, and at no other time; and while they are sustained also by the people…It is not because a man holds a certain class of priesthood that he is to administer in all the offices of that priesthood. He administers in them only as he is called and set apart for that purpose.” (The Gospel Kingdom: Selections from the Writings and Discourses of John Taylor, selected, arranged, and edited, with an introduction by G. Homer Durham [Salt Lake City: Improvement Era, 1941]. 202)
What this implies is yet another way we know there was an apostasy in the former-day church. Once the apostles died and no more were chosen, there was no one with authority to set apart or change or release individuals to or from priesthood offices. There would be none to set new bishops or elders. And once those died, there would be none with authority to set apart or ordain new ones.
How grateful I am that we have the priesthood restored in this dispensation!