One of my students states "... that Christ has to rule on David's throne, I didn't know David had a throne in heaven ..." Is this student coming from a Baptist line of thinking? Thanks for your help.
There are numerous denominations that ascribe to a premillennial form of thinking, Baptist being one of them. All I can say is this person is arguing for a belief that Christ must physically reign here on earth, which is a part of premillenial doctrine.
The root problem is a lack of distinction between figurative and literal speech. Jesus was given the throne of David, as Gabriel told Mary, "He will be great, and will be called the Son of the Highest; and the Lord God will give Him the throne of His father David. And He will reign over the house of Jacob forever, and of His kingdom there will be no end" (Luke 1:32-33). If we state that Gabriel was speaking of a physical throne here on earth, then we have a problem because this earth does not remain forever (notice that it isn't just a thousand year reign). "And: "You, LORD, in the beginning laid the foundation of the earth, and the heavens are the work of Your hands. They will perish, but You remain; and they will all grow old like a garment; like a cloak You will fold them up, and they will be changed. But You are the same, and Your years will not fail"" (Hebrews 1:10-12). Peter is clear that this world will be destroyed. "But the day of the Lord will come as a thief in the night, in which the heavens will pass away with a great noise, and the elements will melt with fervent heat; both the earth and the works that are in it will be burned up" (II Peter 3:10). A physical throne and a physical place cannot last forever.
Perhaps your student would argue that Jesus would take David's throne here on earth and then later move to heaven. The question in response is: Will Jesus still have David's throne there after? The only way to understand Gabriel's statement is that it must be true. Therefore, your student must admit that it is possible to rule from David's throne without a physical throne on the physical earth.
The next question is when did Jesus take possession of David's throne? Peter addressed this in his first sermon: "Men and brethren, let me speak freely to you of the patriarch David, that he is both dead and buried, and his tomb is with us to this day. Therefore, being a prophet, and knowing that God had sworn with an oath to him that of the fruit of his body, according to the flesh, He would raise up the Christ to sit on his throne, he, foreseeing this, spoke concerning the resurrection of the Christ, that His soul was not left in Hades, nor did His flesh see corruption. This Jesus God has raised up, of which we are all witnesses. Therefore being exalted to the right hand of God, and having received from the Father the promise of the Holy Spirit, He poured out this which you now see and hear. For David did not ascend into the heavens, but he says himself: 'The LORD said to my Lord, "Sit at My right hand, Till I make Your enemies Your footstool."' Therefore let all the house of Israel know assuredly that God has made this Jesus, whom you crucified, both Lord and Christ" (Acts 2:29-36). Peter said that David foresaw that Jesus would take David's throne when he was resurrected. Jesus sitting at the right hand of the Father is the same as Jesus sitting on David's throne.
Paul says Jesus is currently reigning and will continue reigning until death is destroyed. "For He must reign till He has put all enemies under His feet. The last enemy that will be destroyed is death" (I Corinthians 15:25-26). "But to the Son He says: "Your throne, O God, is forever and ever; A scepter of righteousness is the scepter of Your Kingdom. ... But to which of the angels has He ever said: "Sit at My right hand, Till I make Your enemies Your footstool"?" (Hebrews 1:8, 13).
Jesus too says he has sat on the throne, "To him who overcomes I will grant to sit with Me on My throne, as I also overcame and sat down with My Father on His throne" (Revelation 3:21).
Jesus' kingdom was never to be taken as a physical kingdom in this physical world. "Jesus answered, "My kingdom is not of this world. If My kingdom were of this world, My servants would fight, so that I should not be delivered to the Jews; but now My kingdom is not from here"" (John 18:36).
David's throne represents Christ's right to rule over God's people. "And Jesus came and spoke to them, saying, "All authority has been given to Me in heaven and on earth"" (Matthew 28:18). This is why we refer to Christ as the Lord.