One way that I've explored this notion is to see the Kingdom of God as an intrusive, interruptive and disruptive force that "breaks into" the world. This idea is nicely captured by C.S. Lewis in Mere Christianity:
Enemy-occupied territory--that is what this world is. Christianity is the story of how the rightful king has landed, you might say landed in disguise, and is calling us to take part in a great campaign of sabotage.In support of this notion I was recently struck by something in 1 Corinthians:
1 Corinthians 15.24-25, 28Here's the phrase that caught my attention: Christ must reign until he has put all his enemies under his feet. Christ's reign takes place during a season of conflict. And when that conflict ends Christ's reign ends.
Then the end will come, when he hands over the kingdom to God the Father after he has destroyed all dominion, authority and power. For he must reign until he has put all his enemies under his feet...When he has done this, then the Son himself will be made subject to him who put everything under him, so that God may be all in all.
Phrased differently, to confess that Jesus is Lord places us in a conflictual and antagonistic relationship with the principalities and powers. To experience the reign of Christ is to participate in his ongoing battle to destroy all dominion, authority and power until that time when God is all in all.