So, why is there a Hell in the first place?
Good question.
God created the Universe, in which he is omnipresent; it all places at all times, sustaining life by his love. He then created mankind, and gave us free will to either follow his wishes for our lives, or to go our own sweet way.
When we go our own sweet way, sometimes we do evil things. If in the process of doing those evil things God were to remain just as present as he is when we are in a state of Grace, we would be destroyed; his holiness would destroy the evil, and it would also destroy us along with it.
In order not to destroy everyone who is being disobedient to his will, God withdraws his presence from that place where they are, during the time when they are acting contrary to his will. This is an act of mercy, in order to give them time to repent and return to him.
The place or existence without the active presence of God is hell. The worst kind of hell is on earth, and involves living a life directly contrary to the will of God, in the full knowledge that he has forbidden that kind of life. And for what is forbidden most strongly, see the ten commandments.
When we accept the Lord and submit once more to his will, then he is able to enter fully into our hearts and our lives, and the more we conform ourselves to his will, the less of hell we encounter, and the more of eternity.