Personally, I believe there are different levels of Hell.
Life on here on earth, is the first level of Hell. How we progress through our lives, following the teachings of God (or Higher Being one choses to believe in ), travelling through life doing the best we can for ourselves and our family and friends, resisting the temptations that may lead to disaster whether it be something like cheating in school, spouse, business to the opposite end of the spectrum of serious criminal activity.
How we live this time on earth, will determine our fate after death. I believe in Purgatory, where we spend time attoning for our sins - great or small - until God determines that we are worthy to enter into His Kingdom....however long it may take.
Then there are the lower levels of Hell. For those who break God and man's rules. I don't believe for a minute that some serial murderer or pedophile - no matter how much he/she might ask for God's forgiveness - ever makes it out of the depths of Hell. Though they may rise up a level or two, and attain God's forgiveness, it doesn't mean that He's going to let them into Heaven, or even as far as Purgatory, to live among those who's worst sin may have only been being a jerk to others.
There are very few who have ever made it through life without sin. Those that have, are either saints or angels. We all have done things we shouldn't...and most of us, when we do those things, realize at the time, "uh-oh, shouldn't have done that!" Doesn't mean we won't commit the same "sin" again, but we are cognizant of the "wrong" of the deed...and there is a voice within us that will ask for forgiveness.
The ability to see the "wrong" and the willingness to attone for the act, will determine our time in Purgatory.
But for those who are just evil, there is no true attonement, no matter how much they may profess their "new found faith in God". It's just another sham to try to con people. For those individuals....there is no Hell that is deep enough or hot enough.