It is very easy to become confused by the present tense verbs used in the writings from 2,000 years ago. When we read the NT scriptures today we have to keep in mind that we are reading historical records preserved by the Holy Spirit. We have to identify who was speaking, and to whom they were speaking.
The pattern and the process of the gospel conversions are universal for all people of all generations. But, many of the historical events were only speaking of the times of that generation, of those people living during the 1st century A.D.
Jesus and Paul weren't speaking of circumstances that their audience would never live to see happen 2,000 years into the future. Jesus was telling them of things and events that were going to affect them directly.
"The ruler of this world"... Their "world" concerned the ruling authority and power under which they lived in the first century A.D. There was the ruler of Galilee and Perea, Herod Anitipater (Antipas), son of Herod I the Great, and who had inherited part of his father's kingdom with the approval of Emperor Augustus.
All of Judea had been a province under Roman rule. This was the 4th beast kingdom prophesied by Gabriel to Daniel (chap. 7) that would be the world power at the time of Christ. So, the word "world" was associated with the kingdom that ruled their lives. It didn't mean the entire scope of all the earth.
All roads lead to Rome became a truism for a reason, and that is because the Roman empire spread over a large territory. It was the known "world" power of the day.
Then, the ruler of this world was either Herod Anitpas, and/or possibly referred to the authority over Anitpas, the Roman emperor.
In Eph. 6:12, Paul said "we" which would include his audience - the Ephesians - and possibly the collective apostles who were the angels / messengers of the gospel. Their struggles were within the ruling powers in "heavenly realms". They were dealing with persecution from the ruling authorities of the Sanhedrin council, and of the Roman procurators. It was a very troublesome time of tribulation.
While we live on this earth we will always face some troublesome times, and hardships in our life. Most always those hardships are caused by wicked and evil ruling authorities. It is proper to recognize the example to all generations, but do not misappropriate the time period to our generation.
The heavenly realms is a reference learned from OT prophesy where the prophets were sent by God to different nations, and they addressed two groups of people... the heavens and the earth.
"Give ear, O ye heavens, and I will speak; and hear, O earth, the words of my mouth." (KJV)
"Hear, O heavens, and give ear, O earth: for the Lord hath spoken, I have nourished and brought up children, and they have rebelled against me."
The prophet did not need to tell God in heaven the words he was about to speak. So, which heavens was the prophet calling in these verses?
The two groups of people in a nation are the ruling powers and authorities over and above the common folk of the land. Heaven was a metaphor for their power and authority over the rest of the people. As God above allows rulers to rise and fall, He raises up nations and throws them down. God is over and above all of the entire earth.
The ruling king was a type of heaven over and above the people of his nation. His kingdom was his heaven, his realm of authority. The "earth" was the people under his rule and authority, and was also the occupied land of that kingdom.
So, "Hear O heavens, and Hear O earth" was in our vernacular "Listen up King, and hear me you people of ____ "- fill in the blank for the nation he was sent to warn.
Following through, then the "end of heaven" (Isa. 13:5) and the "ends of the earth" (Jer. 16:19) were the borders of that nation / kingdom. "Throwing down to earth" was the symbol of ruling authorities being thrown out of their positions of power to be among the people of the land. They would no longer have any ruling authority.
And, "heavenly places" was then the palaces of the kings, and governors, etc. These were "the heavenly places that were to know the manifold wisdom of God."
"To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God," (KJV)
We must use discretion to determine when God is speaking of the kingdoms of men - principalities and powers - and when He is speaking of His kingdom, and His throne. His kingdom and His throne is over all the earth, and He has never abdicated that rule and authority to Satan or anyone else.
For more discussion on this topic see my post "The God of This World And The Prince of The Power of The Air" at ShreddingTheVeil.
The enemy that Paul referred to was an enemy they were facing in the first century A.D., which was two fold: the Sanhedrin council who was terrorizing the people trying to keep the gospel of Christ from undermining their power; and the rulers above them... the Roman emperors.
Jesus drove out the wicked Sanhedrin and Sadducees and Pharisees and Zealots at the destruction of Jerusalem, scattering the power of the holy people (Dan. 12:7) in A.D. 70. The other wicked ruler of that "world" who ruled during the time that the NT books were written was Nero, and he was also dealt with, dying by the sword as he killed by the sword (Rev.13:10).
The enemy in any generation are the children of wrath (Eph. 2:3) or children of disobedience (Eph. 5:6) who will not have God reign over them. These wicked ones will always plague and torment the righteous in every generation. They are the ones pictured who are still outside the city of the New Jerusalem - the church of Christ - the body of Christ - in Rev. 22:15.
That they still exist outside the city indicates that life continued on after the judgment that was pronounced in Revelation. It is a telling clue that Revelation was not an "end of the world" world-wide destruction prophesy. All of the people of every generation since the 1st century A.D. that are baptized into Christ, put on Christ and are entered into the heavenly (ruling authority) under Christ's kingdom, of which the capital city is the heavenly New Jerusalem.
The wicked still exist outside that city unless they repent and are baptized into Christ. Otherwise they will never enter into it.
So, the enemy of the wicked, unrighteous children of wrath are still with us.
(All bold emphasis is mine.)