Each dispensation has had its priesthood. Each has had its priests and its high priests. Each has had its priests, its altars and its sacrifices peculiar to itself. Only priests in any age could worship God; and acceptable worship must ever be in accordance with the law of the priesthood.
During the patriarchal age the father of the family was priest. He offered sacrifice for the family. The grandfather, great grandfather, etc., was high priest over his posterity for all the generations descending from him while he lived. Adam was high priest of the whole race during his life. Then the high priesthood descended to each of his sons for the posterity of each. So Noah was high priest of all the post-diluvian world during his life. Then it descended to each of his sons. Each son was high priest of his branch of the family, in all its generations, during his life. In that age, therefore, as in this, there was a universal priesthood. The priesthood of the Christian dispensation is, in a certain sense, modeled after the patriarchal and in contrast with the Jewish. It is after the order of Melchisedec, and not after that of Aaron. Melchisedec was high priest of that division of the human family to which Abraham belonged, and this distinguished patriarch paid tithes to him. If we do not misinterpret the law of the priesthood of that age, this could have been none other than Shem. Shem was then living, and Noah was dead; and Abraham belonged to Shem's posterity. Hence no one else could be high priest while Shem lived. Many have thought that because it is said he was "without father, without mother, without genealogy, having neither beginning of days nor end of life," that he could not be a man. But they fail to observe that he was without these things in the Aaronic priesthood. For it is said that he had a genealogy, but that it was not in the priestly family. "And they indeed of the sons of Levi that receive the priest's office have commandment to take tithes of the people according to the law, that is, of their brethren, though these have come out of the loins of Abraham; but he whose genealogy is not counted from them hath taken tithes of Abraham." Shem had neither father nor mother, nor beginning of days, nor end of life, in the sense that the Aaronic priests had them; and this is all that is affirmed of Melchisedec.
When God called His people out of Egyptian bondage, and gave them the law, He gave them a new priesthood. The priests were now all confined to the tribe of Levi and the family of Aaron. Men could no longer build their own altars and offer their own sacrifices. On the contrary, they had all to bring their offering to the priests appointed of the family of Aaron, and have them make the offering. With a change of the priesthood came a change of the law. "For," says Paul, "the priesthood being changed, there is made of necessity a change also in the law." The law thus changed was the law of worship through the priesthood. And as it was through this worship that pardon was obtained, the change of priesthood changed the law of pardon. Hence the law of pardon under each priesthood has been different from that under either of the others. After the establishment of the Aaronic priesthood, a descendant of Jacob could no longer build his altar and offer his sacrifice just as he had done before the change. And now a priest under the Christian dispensation can not offer acceptable worship as did either the Jew or the patriarch. The worship that once brought to one the divine blessing would now bring upon him a curse. How strange it is, then, that the denominational world in large measure go back to a different priesthood for their ideas of religion and salvation.
Under the law the kings and the priests were of two distinct tribes. These were of the tribe of Levi; those of the tribe of Judah. Hence it is written: "The scepter shall not depart from Judah, nor a law-giver from between his feet, until Shiloh come; and unto him shall the gathering of the people be." Christ was of the tribe of Judah; hence He, like Melchisedec, is both priest and king. He could not be a priest of the Aaronic order, for he was of a different tribe -- a tribe of which Moses spoke nothing concerning the priesthood. Hence all the efforts to make Him a priest of that kind are refuted by that simple fact. Many insist that Christ was inducted into His priestly office at His baptism, and many vain speculations are based thereon. But this can not be. Christ was not a priest while He was on the earth, says Paul in these words: "Now, if he were on earth he would not be a priest at all, seeing there are those who offer the gifts according to the law" (Heb. viii.4). He could not be a priest on earth, because the Aaronic priesthood was then in force, and He was not of the Aaronic family. Since He could not be a priest while on earth, it is folly to talk of His becoming a priest at His baptism. He could not become a priest till the law of the priesthood was changed, and that was not changed till after His death. The Aaronic priesthood was in full force till His death. He was made high priest, not by the legal ritual, but by the oath of God; and this oath was "after the law," not while it was in force. The law continued till His death, hence it was after His death that He was made high priest by the oath of God. He was a sacrifice when He died, not a priest. He could not be priest and sacrifice at the same time. After His ascension He, as high priest, made atonement with His own blood which He shed as a sacrifice for the sins of the world. Hence a number of facts show the utter folly of claiming that He was a priest among men.
It is through Christ as high priest that we worship God. We can worship acceptably in no other way. There are no other means of access to the Father. Only through and by the priesthood can God be worshiped. Hence the worshiper must become a priest, and then worship through Christ as high priest. All pretensions to approach God in worship, without recognizing Christ as our high priest and mediator, is only an exhibition of an infidel farce. It is an insult to God, because a rejection of His Son. Hence those who do not accept Christ as their high priest cut themselves off from access to the Father. Christ Himself says, "No man cometh unto the Father but by me."
Paul makes it a matter of rejoicing that we have a great high priest who can be touched with the feeling of our infirmities; one that has been tempted in all points like as we are, yet without sin. Such a high priest knows how to sympathize with us, and to make for us all just excuses.
The earthly high priest went once a year, on the great day of atonement, into the most holy place, with the blood of others, to make atonement for the sins of Israel; but Christ, as the high priest of the good things to come, has entered the holy place on high, with His own blood, to make atonement for the sins of the whole world. The offerings made by the priests under the law pertained only to the cleansing of the flesh; but the blood offered by our high priest "cleanses the conscience from dead works to serve the living God."