The Kingdom of the heavens is not the Kingdom of God. It is the Kingdom of the heavens! The kingdom of the angels in the heavens from Adam's sin onwards. The Lord's prayer says:
Thy will be done on earth as it is in heaven (Matthew 6).
So the heavens had God as their king at the time of Jesus' ministry and were doing the will of God. They had Satan as their king before he fell when he induced Adam to sin. The Kingdom of the heavens had drawn near to man at the time of Jesus' ministry because he was about to die and ransom Adam angelically on 33Nisan16, which would enable human saints to be resurrected into the Kingdom of the heavens as angels. Mankind was almost ready to join the kingdom of their heavenly brothers. The point is that the Kingdom of the heavens of Matthew is not another name for the Kingdom of God. This is really important because nearly all churches think that the two are the same and therefore deduce that the Kingdom of God is in the heavens. It is not. It is down here on the earth but run with a different heavenly administration to the one Satan ran from 3992Tishri14 to 2009Tishri14 and then for a further 1266 days of the miracle ministry payback from 2009Tishri14 to 2013Nisan20 and then the heavenly war of Revelation12 starting when Michael stood up fulfilling Daniel12 on 2013Nisan21, and then the heavenly Passovers of Satan and the dragon on 2014Nisan14 and 2014Iyyar14 and then the final 42 months of authority for the human dragon from 2014Iyyar14 to 2017Heshvan14, the earthly Passover of the Dragon, when its unrepentant members go to Gehenna.
A notable exception to normal kingdom nomenclature in Mark is...
10 Blessed is the coming kingdom of our father David! Save, we pray, in the heights above! (Mark 11).
This is the Kingdom that recommenced at the end of the Gentile Times. For Russell sat upon the throne of David, ruling over the sons of Isaac, through the ICC and the sons of Jacob through the JAC from 1914Tishri onwards. Russell must have had some Jewish ancestry somewhere! Or if not then his last successor has.
A notable exception to the normal kingdom nomenclature in Matthew is...
29 But I tell you, I will by no means drink henceforth any of this product of the vine until that day when I drink it new with you in the kingdom of my Father (Matthew 26).
This could not have said: The Kingdom of the heavens, because angels cannot drink wine. The kingdom of my father is the kingdom of God. Paul explains that Jesus is a vassal king of God during the first part of the 1,000 years, then he hands the Kingdom over to his God and father...
24 Next, the end, when he hands over the kingdom to his God and Father, when he has brought to nothing all government and all authority and
power [2018Nisan14, is the end of all
authority and power and government apparatus of Satan. God begins his rulership
on 2018Iyyar19, 2nd 1NC first fruits, through Methuselah, the father of all the
Kings and priests in new earthly Jerusalem].
25 For he must rule as king until [he/God] has put all enemies under his feet.
26 [Until] the last enemy [of the enemies in the verse above], death is brought to nothing [this is not merely the first death which is brought to nothing on 2018Sivan14-17, but eventually all death including even the second death - Hell - will be brought to nothing eventually].
27 For [God] subjected all things under his feet. But when he says that 'all things have been subjected,' it is evident that it is with the exception of the one who subjected all things to him.
28 But when all things will have been subjected to him, then the Son himself will also subject himself to the One who subjected all things to him, that God may be all things to everyone [For it is his Kingdom] (1Corinthians15).
So the first and the second death are finished, brought to nothing, by 3008. So the old JW idea that people who go to Hell are finished permanently is plainly wrong, since even the second death is brought to nothing during the millennial reign of the Christ. So when the Kingdom ends Hell ends. Likewise we read...
4 And he will wipe out every tear from their eyes [this does not mean there will be no tears. It means all tears will be wiped. People will be there to help anyone in distress. If there is an injustice it will be dealt with. If there is a death, there will be a resurrection. If there is an illness, there will be a cure], and death will be no more [neither the first death at the start of the kingdom nor the second sometime after the end of the kingdom], neither will mourning nor outcry nor pain be anymore. The former things have passed away (Revelation 21).
For more on the end of Gehenna see I14.