Hello B,The Kingdom of God teaching in scripture is simple if you start with the right premise. The right premise is grounded in Genesis 1;26-27 and God's purpose for creating man. Man was to "rule" over this present world as God's vice regent. God's rule is first WITHIN man and that is why man was made in the "image" of God and "upright" according to a moral standard - God's righteousness. God's rule was to be THROUGH man over this world. God created a sinless world with a sinless ruler (Adam). The fall destroyed the rule of God IN man and thereby destroyed it THROUGH man. The eternal covenant of redemption is designed to first establish God's rule IN man and then THROUGH man. This restored rule will not be accomplished according to the eternal covenant design until there is another sinless world ruled over by sinless man.
In the mean time,the rule of God is being manifest THROUGH man progressively according to progressive sanctification but never perfectly until "thy kingdom come" when God's will, will be manifest on earth as it is in heaven - perfectly IN and THROUGH man within a sinless new heaven and earth.
In this age that progressive imperfect rule THROUGH man is manifested through the public kingdom administration which began with the family unit in Genesis, and then progressed to the "house of God" within a visible expressive kingdom - Israel. After the cross it then was transferred along with the "keys of the kingdom" to the New Testament "house of God" until the end of this age. Individually, his rule has always been IN man established by spiritual union and then THROUGH man established by progressive sanctification, but institutionally it has been established IN the "house of God."
Do you see this as the beginning of that process?
5 For unto the angels hath he not put in subjection the world to come, whereof we speak.
6 But one in a certain place testified, saying, What is man, that thou art mindful of him? or the son of man that thou visitest him?
7 Thou madest him a little lower than the angels; thou crownedst him with glory and honour, and didst set him over the works of thy hands:
8 Thou hast put all things in subjection under his feet. For in that he put all in subjection under him, he left nothing that is not put under him. But now we see not yet all things put under him.
redeemed man obeying the creation mandate?