In addition to administering the sacred ritual the priests were appointed to be the religious teachers of the people (see Lev 10:11; Deut 33:10; Eze 44:23; cf. Ezr 7:25). At the conquest of Canaan they received no tribal inheritance, though they were assigned 13 towns with surrounding pasture and garden lands (Jos 21:10-19; 1 Chr 6:57-60). They were not to engage in any gainful occupation, but were to be supported exclusively by the tithes and certain prescribed offerings (Lev 10:12-15; 23:17-20; Num 18:11, 20; Deut 18:3-5). Even physically defective persons of priestly families, who might not minister at the altar, were entitled to this sustenance (Lev 21:21-23). At least in the time of Ezra the priests were exempted from taxation (Ezr 7:24).
When serving at the sanctuary the common priest was to wear a uniform made of fine linen (Ex 28:40-42). A linen ephod was the special symbol of the priestly office, but the ephod of the common priest was less elaborate than that worn by the high priest (1 Sa 2:18; 1 Sa 22:18). The high priest's distinctive garb was the blue robe with bells on the hem, the colourful ephod with its embroidered girdle and its breast-piece with the 12 precious stones and the Urim and Thummim, and the mitre, or turban, with its gold plate engraved "Holiness to the Lord" (Ex 28:1-39).
From earliest times, prior to the establishment of a regularly organised priesthood, private individuals such as Cain and Abel (Gen 4:3-5) offered sacrifices and thus performed the essential function of a priest (cf. Ex 19:21, 22). Even after the organisation of a regular priesthood, individuals offered sacrifices under special circumstances (see Jgs 6:18, 24, 26; Jgs 13:16). Throughout patriarchal times the head of the family or tribe usually served as its priest. Thus Noah (Gen 8:20), Abraham (ch 22:13), Jacob (ch 35:3), and Job (Job 1:5) served, each as representative priest of his family.
With the establishment of the theocracy at Sinai and the erection of the tabernacle, God appointed the tribe of Levi to its sacred service in place of the first-born, or head of each family (Num 3:6-13). The tribe of Levi was chosen because of its loyalty at the time of the worship of the golden calf (Ex 32:26-29). Aaron and his sons were set apart to the priestly office, and thenceforth they alone were to serve regularly in this capacity (Num 3:10). The priesthood was hereditary in Aaron's family (Ex 28:1; 40:12-15; Num 16:40; 17; 18:1-8); each of Aaron's male descendants thus automatically became a priest, and served in this capacity unless physically defective (Lev 21:17-21) or temporarily "unclean" (ch 22:3). In Lev 21:10; Num 35:25, 28; etc., Aaron's office is described as that of "high priest," and in Lev 4:3, 5, 16 as that of "anointed" priest. As "the priest" (Ex 31:10) for life, he passed on the right to that sacred office to his eldest qualified descendant. Thus he was succeeded by his son Eleazar (Num 20:28; Deut 10:6), and the latter, in turn, by his son Phinehas (Num 25:11), in whose time the succession to the high priesthood was fixed (vs. 12, 13). In a special sense the high priest represented all Israel, and the subordinate priests ministered in his name and as his representatives. The high priest might perform any of the duties required of the common priest, but the right to enter the Holy of Holies on the Day of Atonement was his exclusively (Lev 16:2, 3, 17, 33, 34). See Atonement, Day of.
In David's time the number of priests had so increased that David divided them into 24 courses, or divisions (1 Chr 24; cf. Jos. Ant. vii. 14. 7; Lk 1:5, 9). At least 2 of the great prophets of the OT, Jeremiah (Jer 1:1) and Ezekiel (Eze 1:3), were priests, and probably Zechariah (see Ezr 5:1; cf. Neh 12:16); some think possibly also Haggai.
Not much is known of the activities of the priests during the monarchy after Solomon, although it is evident that they apostatised at times and supported evil kings (Jer 1:18; 2:8, 26; etc.) Yet, a statement made by Ezekiel seems to indicate that they did not fall so deeply into idolatry as did the Levites (Eze 44:10-15). The priests seem to have retained their professional consciousness during the Exile, and thousands could by means of documents prove their status when the Exile ended (Ezr 2:36-39). They were most probably the chief religious leaders during the exile in Babylonia, among them being Ezekiel (Eze 1:3; 8:1; 14:1-4 cf. 2 Chr 17:8, 9; 23:16; 30:27), and they continued this function in the restoration period after the Exile (Neh 8:2; Hag 2:11, 12). After the return from Babylon only 4 families were at first recognised as legitimately belonging to the priesthood, but the other 20 families eventually succeeded in re-establishing their rights and position, with the result that according to Josephus (Ant. vii. 14. 7) in NT times all the 24 courses which had existed in the time of David were again functioning as priests.
Almost nothing is known of the history of the priesthood under the Persians. Under the Ptolemies and early Seleucids the high priest held both religious and civil power, subject to the foreign king. The priestly aristocracy, living from the tithe of the people and receiving other contributions, became wealthy, and consequently sought eagerly to preserve the political status quo of the nation and to prevent any rebellion that might endanger their lucrative position. They embraced Hellenism under the Seleucids. Yet it was a minor priest, Mattathias, who led the revolt against Antiochus Epiphanes' enforcement of Hellenistic paganism; and his sons, the Maccabees, rallied the nation to win independence from the foreign yoke. Jonathan the Maccabean, and after him his brother Simon, though not of a high-priestly family, gained the office, and the Hasmonaean (Maccabean) line became priest-rulers and later priest-kings of Judea. They became increasingly worldly and considerably Hellenised. Though the majority of the people sided with the Pharisees (the party of strict observance of the Law) the priests were leaders of the religio-political party of the Sadducees. That they could maintain their office under such circumstances was due to the fact that the people by tradition and education were accustomed to rendering honour to the holders of high ecclesiastical offices closely connected with the Temple and the Temple services.
When the Romans came they left the Hasmonaean priest-ruler in office, but later set up Herod the Great as vassal king. During the reign of Herod the Great, high priests were appointed by the king, and this custom continued until the destruction of the Temple in a.d. 70. During this period of 106 years (37 b.c. to a.d. 70) not less than 28 high priests held office. Most of them belonged to 5 leading families, and some were extremely mean and unfit for the office they occupied. Even after a high priest was deposed he was usually considered as high priest or chief priest by the people, hence the plural form "chief priests" in the NT (Mt 2:4; 16:21; 20:18; etc.). Though the "chief priests" sought Jesus' death there were many pious priests, such as Zacharias (Lk 1:5, 6), and many of them joined the infant church (Acts 6:7). With the destruction of the Temple in a.d. 70, the Jewish priesthood vanished, never to experience a revival.
The ministry of the Aaronic priesthood was typical only (Heb 8:4, 5) and, in and of itself, had never been truly effective in securing the forgiveness of sins (ch 10:11). Like the sanctuary in which they served, Aaronic priests were only "a figure for the time then present" (ch 9:9). The ritual law of sacrifices could never "make the comers thereunto perfect" (ch 10:1), since "the blood of bulls and of goats" had no power to "take away sins" (v 4). That priesthood was part of the system "imposed" only "until the time of reformation," when Christ Himself should become "an high priest of good things" (ch 9:10, 11). Only by virtue of His sacrificial death, at the close of the Levitical era, when He "put away sin by the sacrifice of himself" (v 26), could the transgressions of OT times be forgiven (v 15). Throughout OT times salvation was provisional, in the sense that it was conditional upon the yet future death of Christ.
Upon the rejection of the Jewish nation as God's chosen people at their rejection and crucifixion of their Messiah (see Mt 21:40-43), God no longer honoured the Temple as His "house," and henceforth its services ceased to have meaning in His sight (see ch 23:38). Accordingly, the priesthood was changed (Heb 7:12; cf. vs. 15-17; ch 6:20).
Having made one great sacrifice for the sins of all mankind, Christ ascended into heaven and "sat down on the right hand of God" (Heb 10:12), consecrated as our great High Priest and set apart to minister on our behalf in the very presence of the Father (ch 8:1, 2). Only after Christ had offered Himself a sacrifice for sin could He enter upon His special ministry (chs 8:3; 10:12). Only after He Himself had partaken of flesh and blood and been "made like unto his brethren" "in all things" (Heb 2:17), only after He had been "in all points tempted like as we are" and could thus be "touched with the feeling of our infirmities" (ch 4:15; cf. ch 2:14, 18), was He qualified to become "a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people" (ch 2:17). Upon His ascension, therefore, Christ entered "into heaven itself, now to appear in the presence of God for us" (ch 9:24). "The way into the holiest of all was not yet made manifest, while as the first tabernacle was yet standing" (v 8). Like Aaron, He was "called of God" (ch 5:4) and did not assume the high-priestly office of His own volition (v 5). By an oath (ch 7:21), God ordained Him "an high priest after the order of Melchisedec" (ch 5:10; cf. v 6). Thus the priesthood was "changed" (ch 7:12) from earth to heaven, and "seeing he ever liveth to make intercession" (v 25), His priesthood continues forever (v 24). By virtue of His own perfect sacrifice He "needeth not daily … to offer up sacrifice, … for this he did once, when he offered up himself" (v 27). His is "a more excellent ministry," since He is "the mediator of a better covenant" (ch 8:6), which in the strict sense of the word came into force only at his death (ch 9:15-17). This is the "new and living way, … consecrated for us" following His incarnation, "through the veil, that is to say, his flesh" (ch 10:20). We now have a great High Priest over the household of God (v 21) and are invited to "draw near with a true heart in full assurance of faith" (v 22), to "come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need" (ch 4:16) -- Seventh-day Adventist Bible Dictionary.