The word of the Kingdom is heard by different kind of people. Their minds and hearts have different attitudes and that is what decides their course toward or outside the Kingdom. Their minds can be closed, shallow, mixed or open. Depending on these the Kingdom become an opportunity for them or not. The evil one, the world, the riches, the worries are all negative factors in the hearers relationship with the Kingdom. If these have the last word the seed of the Kingdom dies, or does not grow. The positive side of this is that when the mind is open, and the seed can grow and bring fruit, your life identifies with the Kingdom becoming a fruitful place. You became part of the Kingdom, a sign of the Kingdom. So, the relationship with the Kingdom is defined organically. The sons of the Kingdom are people in which the Kingdom manifests itself. The dominion of God is exercised and obedience and service are seen by all.
The Kingdom of heaven coexist with the works of the evil. In God's world the evil one works trying to expand his influence. The separation does not take place. Both realities coexist until the end of times. Only then the separation will be done. So, even if it is a Kingdom, it is not an exclusive Kingdom over the creation. It is a Kingdom which tolerates for the good of those in it the works and schemes of the evil. The whole of humankind is the place in which this happens.

Tags: Jesus, Matthew