[23]  Satan is the ruler of this system of things

After Adam sinned and was thrown out of the garden, Satan was given rulership over mankind in return for his firstborn angelic rights by Michael who had agreed to ransom Adam and therefore been given Patriarchal authority over Adam and all of his begotten children - see U17. Paul says...

14 Nevertheless, death ruled as king from Adam down to Moses, even over those who had not sinned after the likeness of the transgression by Adam, who bears a resemblance to him that was to come (Romans 5).

17 For if by the trespass of the one [man] death ruled as king through that one, much more will those who receive the abundance of the undeserved kindness and of the free gift of righteousness rule as kings in life through the one [person], Jesus Christ (Romans 5).

Death is Satan's name since he brought it about. Jesus is called 'the life', and Satan is called 'the death', or perhaps just plain 'death' to his friends. So he ruled from Adam down to Moses over everyone because of the trespass of the one man Adam. God himself ruled the Jews once they agreed to obey the Law Covenant. Satan continued to rule mankind until the end of his 6,000 years lease on 2008Tishri1. Then he had a further extension in rulership due to a ransom deal for Jesus' miracle ministry which gave him another 1266 days (the length of the period wherein Jesus exercised Kingdom power in Satan's system from the first miracle at Cana on 29Heshvan29 to Pentecost on 33Sivan5) taking him from 2009Tishri14 (the end of Satan's 6,000 year lease) to 2013Nisan20. Then Michael stood up on 2013Nisan21, fulfilling Daniel12:1, And he conducted a war against Satan and his angels as described in Revelation 12. Satan lost the war and lost his heavenly authority over mankind and was thrown down to the earth together with his heavenly administration to possess rotten saints. He is referred to in scripture as the God of this system of things...

3 If, now, the good news we declare is in fact veiled, it is veiled among those who are perishing,
4 among whom the god of this system of things has blinded the minds of the unbelievers, that the illumination of the glorious good news about the Christ, who is the image of God, might not shine through (2 Corinthians 4).
He is 'the ruler of the world' for Jesus said, just before he died:

30 I shall not speak much with you anymore, for the ruler of the world is coming. And he has no hold on me (John 14).

This world therefore began at Adam's trespass. But this ruler will be chucked out:

31 Now there is a judging of this world; now the ruler of this world will be cast out (John 12).

In fact he is locked up for the entire duration of the kingdom of God, as we shall see below. He is deposed immediately before the battle of Armageddon and incarcerated immediately after it.

So the end of the world, is the end of his world, not the end of the planet. It is the end of his system of things which is the current system of things, a system which started at the founding of the world. The founding of the world was the agreement by Jesus to ransom Adam after his trespass. For that agreement gave man a future that Satan had tried to deny us. This was the start of the 7th creative day of Genesis, when God rested from his creative works:

3 For we who have exercised faith do enter into the rest, just as he has said: So I swore in my anger, They shall not enter into my rest, although his works were finished from the founding of the world.
4 For in one place he has said of the seventh day as follows: And God rested on the seventh day from all his works,
5 and again in this place: They shall not enter into my rest (Hebrews 4).

God's last creative act was to make some clothes for Adam and Eve at the time of their sin:

21 And Jehovah God proceeded to make long garments of skin for Adam and for his wife and to clothe them (Genesis 3).

This scripture is literally true, God did make them both clothes. But it also has a greater meaning, a cryptic meaning, a Times crossword meaning as we have seen in I15. So Adam's sin was the founding of the World, the beginning of the current system of things. And the God of this system of things, the ruler of this world is Satan, whose name is death. This is how Satan was able to offer all the kingdoms of the world to Jesus, if he would perform one act of worship to him:

5 So he brought him up and showed him all the kingdoms of the inhabited earth in an instant of time.
6 And the Devil said to him: I will give you all this authority and the glory of them, because it has been delivered to me, and to whomever I wish I give it.
7 You, therefore, if you do an act of worship before me, it will all be yours.
8 In reply Jesus said to him: It is written, It is Jehovah your God you must worship, and it is to him alone you must render sacred service (Luke 4).

Jesus did not say, who are you kidding? You do not own any kingdoms! He knew that Satan did have these kingdoms to give, because he gave them to him for 6,000 years in return for Satan's firstborn angelic rights - see U27. He also knew that Satan had the practice of giving them to various people. But Jesus was not interested in status, or in the glory of men, and he certainly did not want to be first lieutenant to a lying murderer. 

It is of course a huge realisation that Satan is the God of this system of things and the ruler of the world. And we appreciate that if this concept is new to the reader it may cause some serious consternation. But remember that Satan can only act within prescribed limits set by God. God is the referee here, and Satan is just a very dirty team captain, he is not the head of FIFA (although some might disagree). But he does have a lot of supporters. 

God only allows Satan's continued existence and authority in order that we can learn from him without having ourselves to become like him. But nonetheless the world is the Titanic and Satan is the captain, and Sin is the iceberg, but Jesus is the lifeboat. However in his case it will not be the rich ones who get in first, whilst the poor are locked in below, in fact quite the reverse. Anyone and everyone who wants to get in and be saved will be, and the rich, because they falsely believe that they have got it made already, will, in general find it harder to leave their comfort zone. They can be trapped by their own physical success. Come on guys, wake up!!  In fact the scripture says

19 We know we originate with God, but the whole world is lying in the [power of the] wicked one (1 John 5).