When Jesus talks about the “Kingdom of God” he is talking about a spiritual place, a place of the heart, and he explains this when he corrects the Pharisees in Luke 17:20 and 21:
Luke 17:20-21 (King James Version)
20And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, The kingdom of God cometh not with observation:
21Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you.
Having been asked by the Pharisees when the Kingdom of God would come, Jesus replied, “The kinbgdom of God does not come with your carefule observation, nor will people say, Here it is’, or there it is’, because the kingdom of God is within you”.
Therefore the kingdom of God is a condition of the heart. The spiritual leaders of Christ’s time didn’t get it and sadly, many spiritual leaders of our own time don’t get it. It’s God who changes hearts. It’s God who sent his own son to be the sacrifice for all the sins of the world.and it is God who saves us by grace and not by good theology