This sense of 'now-and-not-yet' is also characteristic of the Christian faith. Last month we celebrated Jesus' death and resurrection and at the end of this month we'll be celebrating his ascension. Behind these historical events lie spiritual events. The apostle Paul tells us that on the cross Jesus triumphed over the rulers and authorities in the spiritual realm, taking away their power (Colossians 2:15) and that after his ascension Jesus was given the position of ultimate authority, ruling over all forces, authorities, powers, and rulers (Ephesians 1:20-21). However, we still see evil forces active in the world and we still pray to God “your kingdom come: your will be done on earth as it is in heaven” so where is the triumph and rule of Jesus?
The answer is in the now-and-not-yet nature of the Kingdom of God. The Kingdom of God has been inaugurated by Jesus' death and resurrection but it won't be fully consummated until Jesus returns to judge the living and the dead. As John Piper says
The decisive battle against sin and Satan and sickness and death has been fought and won by the King in his death and resurrection, but the war is not over. Sin must be fought, Satan must be resisted, sickness must be prayed over and groaned under (Romans 8:23), and death must be endured until the second coming of the King and the consummation of the kingdom.
So we can see signs of the Kingdom even now: as people come to a personal relationship with God through Jesus; as people are healed or find in God the courage to cope with tragedy; as those whose lives were dominated by sin or addiction are freed through repentance and the work of the Holy Spirit within them. Yet we also see the continuing effects of a world broken by sin.
As we live in this 'in-between' time we can both rejoice as we see the signs of the Kingdom coming as well as long for the certain future when “There will be no more death or mourning or crying or pain, for the old order of things has passed away” (Revelation 21:4). And on a personal level those who have Jesus as their King can be certain that, although they won't be perfected until Jesus comes again, as the Spirit works in their lives they will become more and more like Jesus, battle by battle, because the war has been won.