In the manifestation of Christ the Saviour it is revealed that He must appear in the three offices of prophet, priest, and king.
Of Him as prophet it was written in the days of Moses: "I will raise them up a Prophet from among their brethren, like unto thee, and will put My words in His mouth; and He shall speak unto them all that I shall command Him. And it shall come to pass, that whosoever will not hearken unto My words which He shall speak in My name, I will require it of him." Deuteronomy 18:18,19. And this thought was continued in the succeeding scriptures until His coming.
Of Him as priest it was written in the days of David: "Yet have I set ['anointed,' margin] My King upon My holy hill of Zion." Psalm 2:6. And this thought, likewise, was continued in all the scriptures afterward unto His coming, after His coming, and unto the end of the Book.
Thus the Scriptures abundantly present Him in the three offices of prophet, priest, and king.
This threefold truth is generally recognized by all who have acquaintance with the Scriptures, but above this there is the truth which seems to be not so well known—that He is not all three of these at the same time. The three offices are successive. He is prophet first, then after that He is priest, and after that He is king.
He was "that Prophet" when He came into the world, as that "Teacher come from God," the Word made flesh and dwelling among us, "full of grace and truth." Acts 3:19-23. But He was not then a priest, nor would He be a priest if He were even yet on earth, for it is written, "If He were on earth, He should not be a priest." Hebrews 8:4. But, having finished His work in His prophetic office on earth, and having ascended to heaven at the right hand of the throne of God, He is now and there our "great High Priest" who "ever liveth to make intercession for us," as it is written: "He shall be a priest upon His [Father's] throne: and the counsel of peace shall be between them both." Zechariah 6:12, 13
As He was not that Priest when He was on earth as that Prophet, so now He is not that King when He is in heaven as that Priest. True, He is king in the sense and in the fact that He is upon His Father's throne, and thus He is the kingly priest and the priestly king after the order of Melchizedek, who, though priest of the Most High God, was also King of Salem, which is King of peace. Hebrews 7:1,2. But this is not the kingly office and throne that is referred to and that is contemplated in the prophecy and the promise of His specific office as king.
The kingly office of the promise and the prophecy is that He shall be King upon "the throne of His father David," in perpetuation of the kingdom of God upon this earth. This kingly office is the restoration and the perpetuation, in Him, of the diadem, the crown, and the throne of David, which was discontinued when, because of the profanity and wickedness of the king and the people of Judah and Israel, they were taken captive to Babylon, when it was declared: "And thou, profane wicked prince of Israel, whose day is come, when iniquity shall have an end, Thus saith the Lord God; Remove the diadem, and take off the crown; this shall not be the same: exalt him that is low, and abase him that is high. I will overturn, overturn, overturn, it: and it shall be no more, until He come whose right it is; and I will give it Him." Ezekiel 21:25-27
Thus and at that time the throne, the diadem, and the crown of the kingdom of David was discontinued "until He come whose right it is," when it will be given Him. And He whose right it is, is only Christ, "the Son of David." And this "coming" was not His first coming when He came in His humiliation, a man of sorrows and acquainted with grief; but it is His second coming, when He comes in His glory as "King of kings and Lord of lords," when His kingdom shall break in pieces and consume all the kingdoms of earth and shall occupy the whole earth and shall stand forever.
It is true that when He was born into the world, a babe in Bethlehem, He was born King and was then and has been ever since King by right. But it is equally true that this kingly office, diadem, crown, and throne of the prophecy and promise, He did not then take and has not yet taken and will not take until He comes again. Then it will be that He will take to Himself His great power upon this earth, and will reign fully and truly in all the splendor of His kingly office and glory. For in the Scripture it is portrayed that after "the judgment was set, and the books were opened," one like the Son of man came to the Ancient of days, "and there was given Him dominion and glory, and a kingdom, that all people, nations, and languages, should serve Him: His dominion is an everlasting dominion, which shall not pass away, and His kingdom that which shall not be destroyed." Daniel 7:13, 14. Then it is that He shall indeed take "the throne of His father David: and He shall reign over the house of Jacob forever; and of His kingdom there shall be no end.” Luke 1:32, 33
Thus it is plain that in the contemplation of the scripture, in the contemplation of the promise and the prophecy, as to His three offices of prophet, priest, and king, these offices are successive, and not all nor even any two of them at the same time. He came first as "that Prophet;" He is now that Priest, and will be that King when He comes again. He finished His work as "that Prophet" before He became that Priest; and He finishes His work as that Priest before He will become that King.
And as He was, and as He is, and as He is to be, so our consideration of Him must be.
That is to say: When He was in the world as that Prophet, that is what the people were then to consider Him; and, as concerning that time, that is what we are now to consider Him. But they at that time could not consider Him as that Priest, nor, as concerning Him in that time, can we consider Him as that Priest; for when He was on earth, He was not a priest.
But when that time was past, He became Priest. He is now Priest. He is now just as truly Priest as, when He was on earth, He was that Prophet. And in His office and work of priest we are now to consider Him just as truly, just as thoroughly, and just as constantly that Priest, as when He was on earth; they and we must consider Him as that Prophet.
And when He comes again in His glory and in the majesty of His kingdom, and upon the throne of His father David, then we shall consider Him as that King, which He will then indeed be. But not until then can we truly consider Him in His kingly office, as He in that kingship and kingly office will be.
In His kingly office we can now truly contemplate Him as only that which He is yet to be. In His prophetic office we can now contemplate Him only as that which He has been. But in His priesthood we must now consider Him as that which He now is, for only that is what He now is. That is the office in which alone He is now manifested, and that is the office in which alone we can now actually consider Him in His own person and procedure.
Not only are His three offices of prophet, priest, and king successive, but they are successive for a purpose. And they are successive for a purpose in the exact order of the succession as given—prophet, priest, and king. His office as prophet was preparatory and essential to His office as priest; and His offices of prophet and priest, in order, are preparatory to His office as king.
And to us the consideration of Him in these offices in their order is essential.
We must consider Him in His office as prophet, not only in order that we may be taught by Him who spoke as never man spoke, but also that we shall be able properly to consider Him in His office as priest.
 And we must consider Him in His office as priest, not only that we may have the infinite benefit of His priesthood, but also that we shall be prepared for what we are to be.  For it is written: "They shall be priests of God and of Christ, and shall reign with Him a thousand years.” Revelation 20:6
And having considered Him in His office of prophet as preparatory to our properly considering Him in His office as priest, it is essential that we consider Him in His office as priest in order that we shall be able to consider Him in His office as king; that is, in order that we shall be with Him there and reign with Him there. For even of us it is written: "The saints of the Most High shall take the kingdom, and possess the kingdom forever, even forever and ever," and "they shall reign forever and ever." Daniel 7:18; Revelation 22:5

His priesthood being the present office and work of Christ, this having been His office and work ever since His ascension to heaven, Christ in His priesthood is the all-important study for all Christians, as well as for all other people.