Gabriel told Mary that her son would someday sit on the Throne of David, which of course, did not exist at that time. Christ now sits on His Father's Throne. When will Jesus sit on David's Throne? Does this assume a literal millennial reign on earth?
30 The angel said to her, “Do not be afraid, Mary; for you have found favor with God. 31 And behold, you will conceive in your womb and bear a son, and you shall name Him Jesus. 32 He will be great and will be called the Son of the Most High; and the Lord God will give Him the throne of His father David; 33 and He will reign over the house of Jacob forever, and His kingdom will have no end.” (Luke 1:30-33)
As the OP mentioned, David's kingdom had already ended long before the coming of Jesus despite prophecies to the contrary. For example Jeremiah 33:17
Thus says the Lord, ‘David shall never lack a man to sit on the throne of the house of Israel.'
David's throne was important because it represented Israel's sovereignty. It also symbolized the authority of the Messiah, also called "Son of David." Christians generally do no accept the idea that Jesus was meant to fulfill the prophecies of the Jewish Messiah, namely to overturn Roman rule and restore Israel's sovereignty. In fact he was crucified for supposedly attempting to do exactly that. Most Christians therefore see such prophecies as relating to the second coming.
Prophecies about David's Throne never referred to a physical throne but to the authority of the Davidic dynasty, which lasted until the time of the Babylonian exile. Commentators have widely varying ideas about how these predictions will be fulfilled. So the prophecy mentioned in the OP need not be understood in terms of a literal millennial reign on earth. But many Christians certainly believe that to be the case.
As Dan Fefferman has pointed out in his answer, the angel informed Mary that she would be with child and would give birth to a son to be named Jesus.
He will be great and will be called the Son of the Most High. The Lord God will give him the throne of his father David, and he will reign over the house of Jacob for ever; his kingdom will never end. (Luke 1:30-33)
That angelic prophecy goes back to the time of King David who wrote:
Your throne, O God, will last for ever and ever; (Psalm 45:6)
Does the Bible say that Christ Jesus will return to Jerusalem to sit on a literal throne of David in Jerusalem where priests will serve in a rebuilt temple offering up animal sacrifices? Because that is what some Christians believe.
Dispensational premillennialism says that the end times will be characterized by the rapture of the church, the tribulation, the restoration of Israel to a place of pre-eminence, and the millennial kingdom. One advocate was Dr. Charles C. Ryrie (1925–2016) whose theology was based on a literal understanding of the Bible. He influenced men like Dr. Charles Swindoll (born 1934). However, the idea of premillennialism and a literal return of Christ to earth predates both those men. The idea first came about in the 1830’s with J. Nelson Darby (Plymouth Brethren) and Philip Schofield who proposed a secret rapture of the church (believers) followed by a literal thousand year reign of Christ in Israel. The raptured church is suspended above it in heaven for the entirety of this period.
But WHY would the risen, resurrected and glorified Christ need to be physically present to rule from Jerusalem for 1,000 years? He already accomplished his mission 2,000 years ago when he cried out “It is finished!” (John20:30) and then gave up his life. He sits on the throne in heaven with no need to lower himself to sit upon a throne in Jerusalem or in a temple made with human hands.
The Bible tells us that when Christ Jesus returns the kings of the earth, the princes, the generals, the rich, the mighty, and every slave and every free man will hide in fear:
They called to the mountains and the rocks, ‘Fall on us and hide us from the face of him who sits on the throne and from the wrath of the Lamb! For the great day of their wrath has come, and who can stand?’ (Revelation 6:15-17)
Yes, some Christians believe Jesus will return bodily to sit on a literal throne for 1,000 years. But Christ Jesus says otherwise. His kingdom is from another place:
>My kingdom is not of this world. (John 18:36)
Well, you have to understand the archetypal significance of thrones. They are symbols of ordered authority emerging out of chaos. The ideal king integrates the forces of chaos and order within himself, and then constructively channels that ability outward. He becomes sovereign over his domain.
So when the Bible speaks of Christ taking his rightful throne, this signifies the establishment of a righteous kingdom governed by divine wisdom. Order, truth and justice rule, not arbitrary power or tyranny.
But it's not primarily about literal kingdoms in the future. That's only part of it. It's more about the individual. You see, each of us must become the master of our own internal kingdom. We have to integrate the chaos within ourselves into higher order. To truly grow up, not just in body but in mind.
Sitting on the throne means to take responsibility. To become King over your own life. Governor of the domain that is you. So Jesus shows the way. He is the archetypal hero. His throne represents the sovereignty of individual maturity, responsibility and virtue.
That's the true meaning. Whether there will also be some literal global kingdom in the future, who knows. But what matters is your own inner throne. That's yours to take, or ignore at your peril. So the question is, will you become king of your own dominion? The alternative is to live chaotically, immaturely, unintegrated. And that's no good for you or for anyone else.
So pursue your throne. That's the symbolic charge of Christ. And it applies regardless of what may happen literally in the future.
Those that believe in a literal interpretation of the Bible, in particular that Jesus and the resurrected saints will rule and teach humanity here on Earth during the Millennium, do indeed believe that Jesus will sit on David's throne.
Some believe that David's throne (i.e. his royal descendants) was preserved by Jeremiah through the daughters of the last king.
See my answers to:
- Is there any historical evidence that would indicate where exactly the ark of the covenant is now located?
- Is the USA mentioned in the Bible?
Briefly, when the last king of David's line was killed, Jeremiah took the king's daughters through Egypt and Spain to Ireland, where they continued David's line as Irish royalty. Later the throne was moved to Scotland, and eventually to England.
Part of one of those answers:
Charles III was crowned while sitting above the Coronation Stone (Lia Fail, Stone of Destiny, Stone of Scone) as were all his ancestors for thousands of years dating back through Scottish monarchs, and Irish before that. Legend says that this Stone is "Jacob's Pillow" (Genesis 28:11). Whether it is that actual stone is irrelevant; what's important is that the story is connected with it.
Some Scottish legends surrounding the Stone of Scone, traditionally used for coronations of Scottish kings in the High Middle Ages, have identified this stone with the Stone of Jacob. Supposedly the Stone of Jacob was brought to Ireland by the prophet Jeremiah and thence to Scotland. The 17th-century writer John Speed, describing the coronation of James I, calls the stone at Westminster Abbey by the Latin name, saxum Jacobi.
— Stone of Jacob - Wikipedia
Jeremiah not only brought the Stone, he brought the royal line of David and the Ark of the Covenant with him to Ireland.