When his followers wanted to proclaim him the Messiah, the divinely anointed king of Israel who would inaugurate the reign of God’s justice upon the earth, Jesus shrank from all that and said, strongly and unequivocally, “My kingdom is not of this world.” Where is it then? Jim Marion’s wonderfully insightful and contemporary suggestion is that the Kingdom of Heaven is really a metaphor for a state of consciousness; it is not a place you go to, but a place you come from. It is a whole new way of looking at the world, a transformed awareness that literally turns this world into a different place. Marion suggests specifically that the Kingdom of Heaven is Jesus’s own favourite way of describing a state we would nowadays call a “nondual consciousness” or “unitive consciousness.”
The Wisdom Jesus, by Cynthia Bourgeault, p. 30.