All the kingdoms will be handed over to the holy people of the Most High

Daniel 7:15-28
I, Daniel, was troubled in spirit, and the visions that passed through my mind disturbed me.
I approached one of those standing there and asked him the meaning of all this. “So he told me and gave me the interpretation of these things.
After them another king will arise, different from the earlier ones; he will subdue three kings. He will speak against the Most High and oppress his holy people and try to change the set times and the laws. The holy people will be delivered into his hands for a time, times and half a time. 
Then the sovereignty, power and greatness of all the kingdoms under heaven will be handed over to the holy people of the Most High. His kingdom will be an everlasting kingdom, and all rulers will worship and obey him.’ 
God gives total dominion to 'one like a son of man'. This was Jesus' favorite title for himself. The kingdom inaugurated at Christ's first coming will be finally realized when he returns.
Opposing God's people in different guises throughout history is the 'little horn', until God finally removes its power. It is from this chapter that Revelation 13 draws its imagery.
Why?
Kingdoms and rulers are changing time to time. They had many strategy and police try to wipe out Christians and Jesus. But Jesus's kingdom is standing firm forever.
Daniel was troubled in spirit,foe he worried the situation of the victims and the terror of those rulers.
How?
We are fighting with the evil one in spirit, but finally we will conquer these kingdom through man of God.