In the 107th section of the Doctrine and Covenants received March 28, 1835, the early saints were told that "there are in the Church, two priesthoods, namely, the Melchizedek and Aaronic. . . ." (D&C 107:1.)
The priesthood, which was defined by President Joseph F. Smith as "the authority given to man to act for God" had been restored six years earlier. On May 15, 1829, Joseph Smith and Oliver Cowdery received the keys to the Aaronic priesthood from John the Baptist, and a few weeks later, the keys to the Melchizedek priesthood were also restored by Peter, James and John.But through this further revelation, the Lord described in more detail the duties involved in holding offices in the the priesthood. In Insights into the Doctrine and Covenants - The Capstone of Our Religion, Monte S. Nyman, a professor of ancient scripture at BYU, wrote on this topic:
"The great revelation to the Twelve (Section 107) revealed that the priesthood of Aaron was conferred upon Aaron and his seed, throughout all their generations, and the literal descendants of Aaron had a legal right to it. . . .
"AlsoT the Lord added some further descriptions of the keys of the Aaronic Priesthood to those given by John the Baptist. The Lord referred to administering the `outward ordinances, the letter of the gospel, the baptism of repentance for the remission of sins, agreeable to the covenants and commandments' (v. 20).
"Section 107 then gives four functions of the MelchizedekT priesthood: (1) the right of presidency, (2) power and authority over all the offices in the Church in all ages of the world, (3) the right to administer in spiritual things, and (4) the right to officiate in all the offices in the Church.
"Thus the Aaronic Priesthood administers the temporal matters of the Church and the Melchizedek Priesthood administers the spiritual. The Aaronic brings a person into the church of God upon the earth and the Melchizedek brings a person into the presence of God through the gospel and ordinances restored to the Church. Both priesthoods are functioning in the Church today."