Satan doesn’t serve God, he has put himself in direct opposition to God. But he is God’s creature so in one sense you’re correct, he is under God’s dominion. However God doesn’t control Satan but he allows him free will, the same as all his creatures. Satan and his minions were once angels (God’s messengers) but turned against God and were cast out of heaven. But they still have all the powers they were created with so they are very strong. But Satan can do nothing on his own, he has no power over us except what we freely give him. And God allows us the freedom to do so if we choose.
I am still bothered by this topic, even though its been discussed before on here, to me, it just makes ZERO logical sense that Satan rebelled against God, and managed to convince 1/3 of the angels he was correct, and basically all that God did to them is kick them out of Heaven, (But he also created Hell for them at the same time), Is this not the same thing as kicking someone out of your house for something, but then go and build them a new house of their own?
I dont understand why God did not just turn Satan and his followers to dust immediately for what they had done…This was no little offense, this was Satan wanting Gods job and power…so, it was a pretty big crime, and yet they still have ALL their powers, basically have immortal lives, have a place of their own, and the worst IMO, the ability to come and go from Hell to influence mankind whenever they wish…so where is their punishment again? LOL
However, if God had destroyed Satan and the fallen angels right when this happened, there would basically be no other choice for mankind, in other words, no evil influence on anyone, I cant imagine that world, but it would probably be close to heaven.Without Satan, people would really not have free will, or the only choice in a world without an evil influence would be God, because there literally be NO evil.
So, in a way, it does seem Satan is needed. I think this is just something we are not meant to know or understand though, because if you look at the facts set forth in the bible and how God deals with sinners, what was done in Satans case does not make sense.
I would be very curious about what the world was like before Satans fall.