Scot McKnight on David MacGregor on the Kingdom of God:
The kingdom of God 'comes.' It cannot be built, ushered in or extended by us – despite the way that many people talk of the mission and responsibility of the church these days – and despite the many prayers offered on Sunday mornings after the collection: 'Lord these monies are for the extension of your kingdom'. Karl Barth maintained that any minister who thinks of his or her task as 'building the kingdom of God' should resign immediately!
Joel Marcus, another New Testament scholar, tells us that it means 'God's Kingly power.' It is for this reason that we must affirm, along with the early church father Origen, that Jesus Christ is the auto basileia – the kingdom of God in person. Jesus Christ is God himself come among us in Kingly power, acting to save us from the powers that enslave us in order to free us to be truly ourselves as we are truly his.