Adam and Eve- together- were to replenish the earth and subdue it.  Then the term subdue is explained by stating they were to have dominion over all living, moving creatures on this earth.  But before they were able to carry out this, sin entered the picture and the idea of sinful man eating of the tree of life caused the Lord to send him from the garden.  He became disqualified for the ideal purpose from which God had called him.  He was now a ruined creation in need of restoration.  The earth followed suit for it found itself cursed and scripture tells us that it is groaning, waiting until the sons of God are revealed.
 
In Job we see such a group of the sons of God.  They meet in heaven, in what must be a prescribed meeting, before God.  Satan is a part of them although at this time he is in a fallen or ruined state as well.  When asked to give an account before God of his doings on EARTH, he is not chided for being there, not asked what right did he have to be on earth.  Nor did God tell him that he had no right to interfere with the lives of men on this planet, but rather expected him to be here bringing trials to the lives of men.  Why...   None of the other sons of God are spoken to in regards to this earth, only Satan.  And being that he is with the sons of God and not told to leave this important council meeting, it would have to be assumed that God in his rightness in not rejecting Satan's presence he recognizes him as ruler of our planet.  Adam was created to take that role, but before he had qualified, he found himself disqualified and could not take the role from Satan.  So Satan still reigns and he reigns with disqualified angels under him.  (Dan 10:13)  They correspond with rulerships here on the earth, and must directly try to affect what the earthly rulers do.
 
God has not replaced them because....no one has qualified.  Our example in the OT is David being anointed when he was a teenager, but did not take over the role of king until God said it was time.  David was a man after God's own heart and yet he had things to learn.  During that time his faith was tested, his resolved to follow God's directions became mandatory, and he developed a network of followers under him so that he had a fully functioning army with those under him, carrying out his orders and his work.  It was after this, that God removes Saul and places the anointed king, David, in his stead.  That is God's example concerning the governing of this earth both from the heavens and the earth.  The appointed fallen ruler will remain in control until a newly qualified is ready to take over.  That readiness is only known to the Father and can only happen with his sanction.
 
The children of Israel tried to go into the promised land and take over the ruling kingdoms without the Fathers sanction, and they failed miserably.  Fortunately they realized that without the Father blessing them, they truly had no chance.  If they had gone in before their lack of faith caused a change of direction for their nation, God's blessing would have been with them.  But since, "without faith it is impossible to please God, for you must know that he is , and that he is a rewarder of them that diligently seek him," their lack of faith caused a change in their direction and they found themselves disqualified from the promise that had been left them.  Others had found themselves disqualified- and subsequently died- before seeing the promise of a new land during their trip from Kadish Barnea for exactly the same reason....lack of faith.  They were on the other side of the blood sacrifice, had been baptized in through the Red Sea and by the pillar of fire, and yet for a lack of faith, failed to receive the promise.
 
And since all of Israel's doings have been recorded in the bible for our example so we could learn from them and not follow their course, we realize that in type, we are just like them.  AS they were called  to be a nation that God could govern through, and thereby all the earth would be blessed (rather than cursed), so we are called to be a part of the heavenly government for the same reason...so all the earth would be blessed.  But, we can be overthrown just as the children of Israel were for the same reason....lack of faith.  But why is there a heavenly government involved?  Because Satan has yet to be replaced from the council of the sons of God.  Because the Prince of Persia (Dan 10:13) is still a bad guy, as are others.  They can not be replaced until those chosen have found themselves in a state of having qualified.  You can see that happening in Rev. 2 and 3.  You have the overcomers and those that have been overcome.  You also have some of the stratagies used by Satan being listed, that work to disqualify Christians.
 
And if Satan can keep us from qualifying....than he retains possession of the rulership.  That is why a key scripture passage is Rev. 5:1-10.    "Who is worthy to open the book and to loose the seals thereof?  And no man in heaven, nor in earth, neither under the earth, was able to open the book, neither to look thereon."  Why is man in this picture....because this is  why man was created and this is what Adam was disqualified from.  I believe it is the title deed of the earth and if you look at this passage with this perspective..."And I wept much, because no man was found worthy to open the book, neither to look thereon."  Why would John cry?  What was so important about this book that he would cry for no man was found worthy- qualified - to OPEN the book, much less read it?  Why is the earth groaning until the sons of God are revealed?
 
Lets look at what the gift-rewards- are, given to those that qualify in Rev. 2,3
 
l.  Eat of the tree of Life-  that means there are those that don't get to eat from it
2.  A crown of life
3. Eating of the hidden manna- that which perfectly sustains for the needs of daily life
4.  power (authority) over the nations
5.  confess his name before the father and HIS ANGELS
6.  pillar in the temple of God
      God's name tattooed? on them
     - also the name of the new Jerusalem
     - also Christ's new name
7.  granted to sit with Christ in his throne
 
How many of these have direct relationship with rulership?  The tree of life in heaven is stated to bear 12 different kinds of fruit.  Twelve is the number of rulership in the scriptures and the tree is here linked with rulership by the use of the number 12.  And only those that qualify- have become overcomers- will be allowed to eat of it.  And the list goes on.
 
But why is it important that there be overcomers prior to Chapter 5 in Rev.  Another type was set up in the beginning of the scriptures.  Adam was with God naming the animals and conversing about whatever was involved in the work they did together.  But then Adam found himself with out a helper and God, setting up a pattern to be followed through scripture, created for Adam a helper, and together they were given the right to have authority over the earth.  They were to rule as a unit.  That is why the Father, prior to His ruling on the earth, called a bride for himself into exsistence.  They had to go through their qualifiying period prior to God coming to this earth to reign with them.  Well, we know how that went, and later the Father said that he divorced Israel and his presence returned to Heaven.  Now the Father is calling a bride- through the work of the Holy Spirit-into exsistence for His Son.  He must, as in the type, have a bride prior to his taking over rulership.  That is why John the Baptist and Christ told those who would listen to repent and turn back to God, for the kingdom of Heaven (of the Heavens) was at hand.  They could have accepted him, thereby becoming Christ's bride, but since that was not the Fathers plan- for Israel will once again be the Fathers bride- there is a new nation from which the Holy Spirit will draw a bride.  This bride must be complete prior to Christ being able to take over the rulership from the heavens and then from the earth.  (Satan is not cast out of Heaven with a 1/3rd of the stars-disqualified ruling angels under Satan-until the last half of the tribulation)  The opening of the book is the beginning of the process to take over that which is now in the hands of the Son.  Christ and His bride-his helper- will begin to function first in the heavens and later it will reach down to the earth as Christ seeks to set up his kingdom in both realms.