The function of priests, as outlined, centers on their role as intermediaries between God and the people, embodying and promoting holiness. Priests, through their religious instruction and living example, combined with the services conducted at the tabernacle or temple, are called by God to be constant reminders to the entire nation and church that everyone is to be holy as God is holy. Their responsibilities include offering gifts and sacrifices for sins, acting on behalf of men before God, since men are personally cut off from direct access to Him in the context of worship arrangements. Under the Old Covenant, priests and Levites were visible and audible links between God's call to holiness and its fulfillment in His Kingdom. Aaron was appointed as high priest, and his sons—Nadab, Abihu, Eleazar, and Ithamar—as priests, to organize Israel toward becoming a holy nation. Their roles demanded strict adherence to God's standards, with no deviations or innovations permitted, as seen in the severe consequences faced by Nadab and Abihu for offering profane fire. Physical perfection was required, disqualifying those with defects from serving at the altar until healed, reflecting the perfection of God Whom they represented. Priests were also bound by stringent ceremonial and personal conduct rules, such as restrictions on contact with the dead, marriage to virgins from their own lineage, and abstaining from practices associated with pagans, all to maintain their holiness. Under the New Covenant, all believers are considered a royal priesthood, serving under the High Priest, Jesus Christ. They are to be visible and audible links in the same purpose of holiness, acting as priests to each other with responsibilities to reflect God's holiness in conduct and attitude before Him, the world, and the church. The Old Testament records of priestly duties and standards are deliberately designed for learning, emphasizing the high level of holiness God demands from those called to serve Him in such intimate association with the Father, the Son, and each other within His family.

Jesus Christ, as our High Priest, holds a central role in the worship of God, and we, being in Him, are part of His priesthood. Since we are united with Him, His work becomes our work, and we are called to follow Him wherever He goes, both now and into eternity. The Bible reveals a progressive development of priesthood, beginning simply and becoming more complex over time, as seen in God's pattern of purpose. In Exodus 19:5-6, God declares that if the children of Israel obey His voice and keep His covenant, they shall be a kingdom of priests and a holy nation, indicating a dual role of priesthood and nationhood. This concept is echoed in I Peter 2:9, where believers are described as a chosen generation, a royal priesthood, and a holy nation, tasked with proclaiming the praises of Him who called them out of darkness into His marvelous light. As part of Christ, we are spiritual Jews, integrated into the temple that is central to the worship of God, with Jesus Christ as the Head and High Priest. Revelation 5:9-10 envisions a future where the redeemed from every tribe, tongue, people, and nation are made kings and priests to our God, reigning on the earth under Christ. While the role of a king often garners more attention due to its broad responsibilities, the specific duties of a priest are equally significant, though less familiar in their details. Initially, individuals acted as priests for themselves or their families, a role that expanded to represent the nation and ultimately the church, culminating in Jesus Christ as the ultimate High Priest. Historical records across nations, including those no longer in existence, mention priesthoods serving various gods, often with a high or chief priest who held significant influence in governance, sometimes second only to the king. In Joshua 14:1, Eleazar the priest is notably involved alongside Joshua in distributing the inheritance of the land of Canaan to the tribes of Israel, underscoring the high priest's prominent role. The Israelitish priesthood, established by God through Moses, is deemed far more critical to God's purpose than other roles like that of a judge, demanding strict adherence to divine standards in both teaching and personal conduct. Examples from the forebears of Israel highlight early priestly interactions, such as in Genesis 41:45, where Joseph marries Asenath, daughter of Poti-Pherah, a priest of On, ensuring his acceptance in Egypt due to the high status of priests. In Genesis 14:18-19, Melchizedek, king of Salem and priest of God Most High, blesses Abram, conferring good upon him, possibly with encouraging words, and shares bread and wine, symbolizing spiritual and physical sustenance. Abraham's high regard for Melchizedek is evident as he tithes to him and accepts his offerings without hesitation. Additionally, in Exodus 12:3-6, before the formal appointment of a priesthood, the head of each household acts in a priestly capacity during the first Passover, suggesting a familial responsibility that carries a biblical basis, even if not formally commanded.

The function of priests is a vital aspect of God's plan, as we are called to be a royal priesthood, both now and in the future Kingdom of God. Revelation 5:10 declares that we are made kings and priests to our God and shall reign on the earth, highlighting the dual role we are to prepare for. This priestly responsibility is not merely a future expectation but a present reality, as I Peter 2:9 and 2:5 affirm that we are a chosen generation, a royal priesthood, built as living stones into a spiritual house to offer spiritual sacrifices acceptable to God through Jesus Christ. These sacrifices are not just for the future; we must practice them now to be prepared for our roles in the World Tomorrow. A priest's primary function is to assist people in accessing God, facilitating union with Him through mediation and reconciliation between God and men. This role involves being a mediator who brings together, reconciling differences, and also serving as a teacher of a way of life to improve upon the established reconciliation. In the Old Testament, priests had unique access to God, entering areas of the Temple such as the Holy Place, and on the Day of Atonement, the high priest entered the Holy of Holies to make offerings before God. This access allowed priests to serve God personally and minister to others by representing the average Israelite before God, offering something of value to both parties. Priests also offer sacrifices, a central duty seen in the vast number of offerings required during the Feast of Tabernacles, which symbolizes the Millennium. Numbers 29:12-13 details the extensive sacrifices during this feast, indicating the significant priestly work that will be required in the future, surpassing all other times in God's plan. While physical animal sacrifices were offered in the past, the concept now extends to spiritual sacrifices, reflecting dedication and service. Additionally, priests function as saviors and judges, as seen in Obadiah 21, where saviors on Mount Zion judge during the millennial period, delivering and teaching Israel as they are regathered from captivity. The essence of sacrifice, a key priestly act, is to give a gift to God to establish or renew fellowship with Him. Sacrifices are not merely about death but include the offering of a life lived in devotion, commitment, and service. Romans 12:1 urges us to present our bodies as a living sacrifice, holy and acceptable to God, which is our reasonable service. This mirrors the example of Jesus Christ, who offered His life entirely in obedience to God, setting a pattern for us to follow as New Testament priests preparing for our future roles. Through such sacrifices, we build and strengthen our relationship with God, renewing it daily to maintain at-one-ment with Him.

Priests stand between God and worshippers as agents provided by Him for the purpose of helping worshippers by means of instruction and example to become holy as God is holy. Growing in holiness through the sanctification process is the single most important requirement for filling the priestly position because the position is so important. Holiness reflects a similitude of God. Under both the Old and New Covenants God's overall purpose is to create a holy nation. All are called to be part of the priesthood and are in training for that responsibility. The priest promotes unity of the brethren by being in unity with God. This unity flows from the Father through the Son through the priesthood and out to those the priesthood is serving. The priest promotes conduct among the brethren that is in harmony with the responsibilities of the relationship with God. Humility meekness patience and forbearing with one another in love produce holiness because this quality of unity holds things together. The love for God and the brethren motivates the priest's conduct. A priest must study God's Word and put it into practice because the Word of God is essential to the life and work of a priest. The Word cleanses the mind. Every high priest is appointed for men in things pertaining to God that he may offer both gifts and sacrifices for sins. He can have compassion on those who are ignorant and going astray. No man takes this honor to himself but he who is called by God. The priest must be attuned to God's Word and the appeals of the people so that he can get to the heart of a matter and rightly counsel people. The priest must handle responsibilities in a consecrated way and walk before the people in an upright and holy manner.

Priests in ancient Israel consisted of all qualified males from the tribe of Levi, with high priests drawn from Aaron's family. God claimed the entire tribe of Levi for lifelong service devoted to maintaining correct worship first in the tabernacle and later in the temple. Levitical priests were required to meet strict standards of physical and moral purity before offering sacrifices. Physical perfection was demanded so that no priest with defects such as blindness, lameness, deformity, disease, or injury could approach the altar or the veil, since such imperfections represented the effects of sin and would profane God's sanctuary. Within this tribe Aaron and his descendants held special status as high priests with the highest responsibility to serve in the holy place and the most holy place. The function of the priest was to build a bridge between man and God. Priests represented God before the people and the people before God while guarding and defending His truth and creation. Although not every Israelite ministered in the tabernacle or temple, the entire nation functioned in a priestly capacity by representing God to surrounding nations and performing duties in support of the priesthood. Adam's original responsibilities of guarding the garden, upholding Sabbath observance, and protecting creation from defilement illustrate these same priestly functions. This physical priesthood served as a shadow of the spiritual royal priesthood that is the church. Members of the church are called to offer spiritual sacrifices acceptable to God through Jesus Christ, who as the perfect High Priest purifies His people continuously and introduces them into the Father's presence. Their priestly duties include presenting themselves as living sacrifices, maintaining purity of heart and conduct, stirring up love and good works among one another, and assembling faithfully for worship and encouragement. These responsibilities demand sincere reverence, consistent obedience, and freedom from attitudes of contempt, weariness, hypocrisy, or presumption toward God's service.