In the year of 1829 during the month of May on the fifteenth day, Joseph Smith and Oliver Cowdery had been translating the gold plates as they had been for some time when they came across a passage talking about Baptism for the remission of sins. Their curiosity on the subject led them to pray about it. As this was a personal and sacred matter, they found a private place where this could take place, in the woods.
While praying to the Lord about this baptism spoken of in the plates, a holy angel descended from a pillar of light into their presence. With these words, while laying his hands upon their heads, he conferred the keys of the Aaronic Priesthood upon Joseph and Oliver:
Upon you my fellow servants, in the name of the Messiah, I confer the Priesthood of Aaron, which holds the keys of the ministering of angels, and of the gospel of repentance, and of baptism by immersion for the remission of sins; and this shall never be taken again from the earth until the sons of Levi do offer again an offering unto the Lord in righteousness.
This holy messenger of the Lord was the John of the New Testament, the John that baptized Christ in the Jordan River. John the Baptist commanded the two men to enter the river in the woods near where they were and baptize each other – Joseph first baptizing Oliver who then baptized Joseph. In the same order they then ordained each other to the Priesthood of Aaron, or the Aaronic Priesthood.
John, the angel, acting under the same apostolic Peter, James and John of the the New Testament, told these two newly baptized and ordained men that in due time the three above mentioned apostles would come to them to ordain them to the Priesthood of Melchizedek, or the Melchizedek Priesthood.
This due time came a few weeks later when Peter, James and John appeared unto Joseph and Oliver to ordain these two men to the higher Priesthood. By the laying on of hands this was done. Joseph Smith was called as the first Elder of the Church and Oliver Cowdery was called as the second Elder of the Church.