Question: Is it necessary to believe in a literal 1,000 year kingdom? Can’t “the kingdom” refer to the eternal new heaven and earth?
Answer:

The fact that this number is repeated six times in this passage indicates that the figure is to be understood literally. Why the repetition if it is not to be taken literally? The Old Testament also teaches the literal 1,000 year reign of Christ on earth. The Davidic covenant between God and the nation of Israel unveils that Jesus will reign from the throne of David in Jerusalem for a 1,000 years. Key texts which should be interpreted literally are: Ps 2:1-9; Isa 9:6-7, 11:1-2, 55:3; Jer 23:5-8, 33:20-26; Ezek 34:23-25, 37:23-24; Luke 1:32-33.
If you don’t use the historical-grammatical method, the text can be made to mean any number of things. The Word of God becomes “putty in the hand of the interpreter.” In Genesis 17: 8, God made a covenant with Abraham in which God gave to him and his descendants the land of Canaan. When any student of the Word of God reads this text, they all interpret it literally. Abraham received actual literal dirt — miles and miles of real land.
The leadership at FBC would interpret the Scripture concerning the Davidic Covenant the exact same way that we interpret the Genesis 17 passage – the Abrahamic Covenant) — literally. Otherwise Abraham never really received any literal land. It must have been a spiritual land. (I say this in jest.) As the land of Canaan was a literal place given to Israel, so the 1,000 year reign of Christ will literally happen. Jesus will sit physically on a real throne, in the physical city of David here on earth.