God made Abraham a simple promise, “In your seed all the nations of the earth shall be blessed” (Gen. 22:18). The apostle Paul identifies this seed. “Now the promises were spoken to Abraham and to his seed. He does not say, ‘And to seeds,’ as referring to many, but rather to one, ‘And to your seed,’ that is, Christ” (Gal. 3:16). How does this Jesus bless all the nations. He is “the Lamb of God who takes away the sin of the world” (Joh. 1:29).
The writer to the Hebrews explains it this way:
For Christ did not enter a holy place made with hands, a mere copy of the true one, but into heaven itself, now to appear in the presence of God for us; nor was it that He would offer Himself often, as the high priest enters the holy place year by year with blood that is not his own. Otherwise, He would have needed to suffer often since the foundation of the world; but now once at the consummation of the ages He has been manifested to put away sin by the sacrifice of Himself (Heb. 9:24-26).
As our great high priest, Christ offered Himself as a sacrifice to take away the sins of people “from every tribe and tongue and people and nation” (Rev. 5:9). The Old Testament temple, priesthood, and sacrifices looked forward to this. Consider Isa. 56:6-7. I’ve added the italics.
Also the foreigners who join themselves to the LORD, To minister to Him, and to love the name of the LORD, To be His servants, every one who keeps from profaning the sabbath And holds fast My covenant; Even those I will bring to My holy mountain And make them joyful in My house of prayer. Their burnt offerings and their sacrifices will be acceptable on My altar; For My house will be called a house of prayer for all the peoples.
Jesus Christ was and is the great High Priest for all the nations. Therefore, Psa. 96:2-3 declares, “Proclaim good tidings of His salvation from day to day. Tell of His glory among the nations, His wonderful deeds among all the peoples.” Our Lord also tells His disciples, “The gospel must first be preached to all the nations” (Mar. 13:10). Christ, the prophet to the nations, reveals Himself as the great high priest for the nations. This is possible because Christ is King of the nations.
His Great Commission, Mat. 28:18-20, begins with a confession of Kingship. “All authority has been given to Me in heaven and on earth.” Christ is King of kings and Lord of lords (1 Tim. 6:15; Rev. 17:14, 19:16). With this authority, Christ commissions His disciples, “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit, teaching them to observe all that I commanded you.” Bring the nations under the sway of My teaching and power. Make the nations a visible part of My kingdom and all of heaven will cry, “The kingdom of the world has become the kingdom of our Lord and of His Christ; and He will reign forever and ever” (Rev 11:15). Christ’s commission rests on His Kingship.
Proclaim Christ as prophet to the nations. Present Christ as priest for the nations. Don’t, however, undercut this message. Declare Christ as the King of the nations. This is foundational. “If the foundations are destroyed, what can the righteous do?” (Psa. 11:3).