The Bible has much to say concerning priests and the priesthood. We know for a certainty that there were/are priests under the Patriarchal dispensation, the Mosaical dispensation and in the present, Christian dispensation. You won’t find much concerning priests under the Patriarchal age, but enough to know there were such. The duties of a biblical priest was that of one who was an intercessor between man and God. They offered sacrifices for themselves and for others.
We know that Adam’s family offered sacrifices. It is evident that they were able to converse with God and make their own offerings to him, etc. But you don’t hear the word priest mentioned at that particular time. There are only sparse references to priests throughout the Patriarchal period.
The first mention of a priest is found in Genesis 14:18 where it tells of Abraham encountering the king of Salem, a priest named Melchizedek. Abraham paid tithes to him and he is referred to as priest of the most high God in that verse. There is no mention as to how these men were appointed to such an office, but since this period of time was one when God was in regular contact with man, it can be assumed that the office was given them directly from God.
Also under that same dispensation we know that Joseph, when he had won the favor of Pharaoh, was given a wife who was the daughter of Potipherah, priest of On. (Genesis 42:45)
And finally, as time drew nearer to the Mosaical period, we learn that Moses himself, slew an Egyptian and fled the area to the land of Midian where he married the daughter of Jethro who was a Midianite priest. (Exodus 2:16-22)
Again, we are not given details as to the part these men played under this dispensation. But since their duties have always been, where known, to intercede for man to God, whether to make personal requests or to offer sacrifices for, is felt to be the same under all dispensations.
When God chose Abraham’s seed to be his people in furnishing the lineage to Jesus Christ, he picked Moses to be the leader of those people. After their being miraculously freed from the Egyptian bondage, and when they arrived at Mount Sinai, God gave them an entirely new law, with many specifics. This one was written where it would not have to depend upon the patriarchs to pass it on verbally from generation to generation. And this one also spelled out the duties of those chosen as priests as well as who they would be.
God picked the descendants of Levi to be set apart. They were given the responsibility of caring for the religious aspects of the Israelites. They would build and maintain the tabernacle and the other items used in worship. When they moved, it was their duty to transport the many items belonging to their tabernacle and worship. Moses and Aaron were brothers of the tribe of Levi and Aaron was chosen to be the High Priest. His male descendents would be priests and no others were eligible. This was part of the law given to Moses and was permanent and sure for the generations of the Israelite nation.
The priestly duties were many and strict. The tabernacle was built with an inner court, and outer court and an enclosed area within the inner court called the ‘Most Holy Place’. The inner court was the ‘Holy Place’. Only the priests could enter the ‘Holy Place’ and only the high priest could enter the ‘Most Holy Place’. And Aaron, the high priest, could only enter the Most Holy Place once each year where he would personally offer a sacrifice for his own sins and another sacrifice for the sins of the people. The priests offered sacrifices daily for the many varied sins and different sacrifices.
The strictness in the exact observance of their duties was tragically shown by the careless erring from the specifics by two sons of Aaron, Nadab and Abihu. One morning as they prepared for the days work of sacrifices, we encourage everyone to observe the two verses as to what happened.
And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not. And there went out fire from the LORD, and devoured them, and they died before the LORD. (Leviticus 10:1-2 KJV)
These men had met the strict rules required to be named priests. They did not do something here that God had told them not to do. All they did was something which he had not told them to do. Many people today will tell you that strict obedience is not necessary as long as your heart is right.
Now we come to the third dispensation, that of the Lord’s spiritual kingdom on earth, the Christian dispensation. A massive change has occurred in the law. Jesus took the Mosaical law out of the way, nailing it to his cross. (Colossians 2:14)
Be aware, Jesus was not a priest while he was here on this earth. He lived under the Mosaical law and was not qualified to be a priest under that law. He was from the tribe of Judah, not the tribe of Levi and so not a descendent of Aaron. But many changes were made at his death. He became our High Priest and remains so where he intercedes for his faithful children here on earth. He entered into the Most Holy Place and made an atonement for our sins once and for all to those who will obey him. His kingdom, his church here on this earth, is the holy place where the saints are all entered in. We have been given the position of priests where we can plead our own case directly to God.
Those in his kingdom are proclaimed as priests, offering our lives as a living daily sacrifice unto God.
Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ. (1 Peter 2:5 KJV)
But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light: (1 Peter 2:9 KJV)
The Christian Priesthood:
Just as the Levitical priests were consecrated to their office by the washing of water, even so, men and women today may enter upon their priestly functions as Christians. This they do by drawing near to God with a true heart, having their hearts sprinkled from an evil conscience, and their bodies washed with pure water (cf. Heb. 10:22). That this transition occurs at the point of baptism is beyond successful dispute (cf. Acts 22:16; Eph. 5:26; Tit. 3:5). Professor Donald Hagner, of Fuller Theological Seminary, says that the term “water” (in Hebrews 10:22) is “almost certainly” a reference to “Christian baptism” (New International Biblical Commentary — Hebrews, Peabody, MA: Hendrickson, 1990, p. 165). (The Christian Courier: Exploring the Concept of Priesthood)