The LDS Church teaches that the priesthood is the power and authority of God to act on His behalf. All worthy male members enter into the priesthood. Only they can properly administer the ordinances necessary in obeying the gospel of the LDS Church. Certain priesthood holders are given the authority to hold priesthood keys which help them direct a congregation.
There are two types of priesthood: the Aaronic and the Melchizedek.
The Aaronic Priesthood serves as the entry point into the priesthood for boys twelve and older and adult male converts. This priesthood is responsible for the church’s temporal affairs. They have the authority to act in the name of the Lord and help others receive blessings available from obeying the gospel.
The Melichezedek Priesthood is for all worthy adult male members of the LDS Church. “Through the authority of the Melchizedek Priesthood, Church leaders guide the Church and direct the preaching of the gospel throughout the world. This greater priesthood was given to Adam and has been on the earth whenever the Lord has revealed His gospel. It was taken from the earth during the Great Apostasy, but it was restored in 1829, when the Apostles Peter, James, and John conferred it upon Joseph Smith and Oliver Cowdery.” (True to the Faith, p. 101)
Biblical Christianity teaches:
Every male and female believer is a member of the holy and royal priesthood (1 Peter 2:5-9). They are holy and righteous in God’s eyes because of the perfect life and sacrificial death of Jesus Christ. No other sacrifice is required. Members of the royal priesthood serve God by offering themselves as “living sacrifices, holy and pleasing to God.” (Romans 12:1)