If the kingdom has come in an initial but not yet consummative form, what does its current form involve? … The emphasis of the kingdom picture in the present phase is not on realm, but rule.
Nonetheless, a realm is envisioned. Jesus’ realm is the world as it is manifested in his scattered followers. The kingdom is contained in Jesus’ total authority over salvific blessings, an authority that is present over everyone. The presence of his rule in believers anticipates his coming to earth to rule physically, when he will exercise dominion and judgement over the earth.
Darrell Bock, A Theology of Luke and Acts (2012), 207