From Bart Ehrman’s Apocalyptic Prophet of the New Millennium:
Moreover, when Jesus refers to this coming Kingdom, in which God will reign, he does not appear to be thinking in purely symbolic terms about God becoming the ruler of your heart. For he often describes the Kingdom with graphically tactile language. Jesus talks about the Kingdom of God “coming in power,” about people “entering into” the Kingdom, about people “eating and drinking in the Kingdom” with the Jewish ancestors, about his disciples serving as “rulers” of the Kingdom, sitting on actual “thrones” in the royal court.
Truly I say to you, in the renewed world, when the Son of Man is sitting on the throne of his glory, you (disciples) also will be seated on twelve thrones, judging the twelve tribes of Israel (Matt. 19:28; cf. Luke 22:30).
And there will be weeping and gnashing of teeth when you see Abraham and Isaac and Jacob and all the prophets in the kingdom, but you are cast out; and people will come from east and west and from north and south and recline at table in the kingdom of God (Q: Luke 13:23—29; cf. Matt. 8:11—12).
Such references are scattered throughout the tradition, and rather than writing them off—for example on the grounds that we ourselves don’t imagine that God will actually, literally, establish a kingdom here on earth—we should take them seriously. Jesus, like other apocalypticists living before him and afterwards, evidently thought that God was going to extend his rule from the heavenly realm where he resides down here to earth. There would be a real, physical kingdom here, a paradisal world in which God himself would rule his faithful people, where there would be eating, drinking, and talking, where there would be human co-regents sitting on thrones and human denizens eating at banquets.