Satan rebelled, thought he could be God, God could not allow that to go unpunished thus hell is created.
Satan and his angels are going there.
Mat 25:41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:
Then man rebels against God and does not listen to His word, so man and woman must now go there as well, for they have sinned against God.
God cannot allow sin into His presence so there must be a place for those that rebel and reject Him, hence Hell.
Now Remember God is everywhere, God is light so He had to create a place, a terrible place He would not go thus no light. A place that could not see Him, out of His presence.
That was what He did for the devil and his angels, and now because humans sinned in the garden, because they rebelled against God, they too will share a fate never intended for them.
So when the average person comes to you and says how can God send anyone to Hell, then you can tell them He is not.
He never intended that for man but because we are sinners, because we sinned, disobeyed and rebelled, He had no choice but to create a place for those that chose that path.