The Already and Not Yet Kingdom — Mark 1:15

Jesus' inaugural proclamation in Mark 1:14-15 — "the kingdom of God is at hand; repent and believe" — sets the tension of New Testament eschatology: the kingdom has arrived in him, yet awaits consummation.

N.T. Wright — The Resurrection of the Son of God, while Augustine — City of God. The parables of Matt 13:31-33 picture a kingdom that grows hiddenly before its harvest.

The 'already' is secured by the resurrection of 1Cor 15:20; the 'not yet' awaits the new creation of Rev 21:1. Between them the church lives by hope.