Some exegetes of the Bible have affirmed that the Kingdom of God is the church, others  the life in the afterlife. The Kingdom of God is an ethical doctrine, which establishes a relationship between man and the divine, it is here and now, it is the culture of excellence, it is the domain, order, of the divine perfections.
The Kingdom of God has a double aspect (one internal, other external):
                                         a) The Kingdom of God as the transformation of man to his nature
                                         b) The Kingdom of God as the Correct Order of the society
a) A nature Aristotle tells us is what the being tends in his development. Example, the nature of the worm is the butterfly. So what is the nature of man?
We can say that the nature of man is the adulthood or adult life. And what is the adult man? The adult man is the man gifted by the counsel. The gift of counsel is listening (perceive with attention), meditation (with intuition and inspiration) and decide with creativity and discernment.
Practical cases of counsel are Jesus and the prostitute (John 8), Jesus and the denarious (Matthew 22). The characteristics of the gift of counsel are exactness and accuracy, across the gift of counsel we emulate God, we solve what is presented to our judgment as God in person. It is in this what  the state of grace consist.
Emulate remember is to imitate capturing the personality of the imitated, through the gift of counsel we capture the spirit of God for the resolution of what is presented to our judgment.
We can say definitely that man's nature is the conformity the to God.
b) The Kingdom of God has an external aspect that is the power in the hands of the adults, or to say, in the hands of people gifted with the counsel.
Recall that the spiritual power is the power perfected by the dominion or self-control. Self-control or dominion is a fruit of the spirit. It is the mastery over one's mind and one's thoughts. The domain, in practical terms, became the gift of Counsel.
When the power is in the hands of persons gifted with the own domain or gift of counsel the common good and ultimately a government of divine characteristics is established.
The Kingdom of God as the Domain of Wisdom or Domain of the gifts of God represents the only possible way for mankind. The kingdom of God is within us, inside and outside us.