What purpose does it truly serve? Is there anything one person can do that is so horrible that they deserve an eternity of indefinite torture? No bible quotes please just opinions. The bible can be interpreted every which way and there are verses supporting both sides of either arguments. What purpose does an eternal hell serve? Or an afterlife for that matter. What do we accomplish by being alive after death, or more importantly what does god? Supposedly only humans are allowed this divine privilege. Perhaps other creations are considered inferior? Just curious what anyone thinks on the matter.
Punishment for an egotistical, self-serving, self-worshipping, evil-natured lot.
Why not ask yourself if there is a single person who, if they had the ability to torture for an eternity, would. The answer would be a resounding yes and yet we think God is horrible because an immortal cannot die, therefore any punishment would logically be 'forever'.
The afterlife matters because that was God's intention to start with and if He is immortal, then obviously if He wanted to create something, it would therefore also be immortal. Don't forget it was we who failed, not God, in the Garden.
As to other creations (and sorry for the scripture, but it answers the question):
Ecclesiastes 3:21
(NIV1984)
21 Who knows if the spirit of man rises upward and if the spirit of the animal goes down into the earth?
If you knew your scriptures you would know that no one claimed that we are the only 'creation' that would be allowed this 'divine privilege'. The fact is that we just don't know everything and won't until we die (if you believe).
It's very easy to ask this question from the comfort of our homes with a/c, plenty of food, a roof, warmth, friends and family, jobs and a reasonably free and hopeful future.
Now, ask those who live in hellish conditions of poverty and starvation if they hope for something better after they die. To think that God would allow that to be all for them is ludacris and is the very purpose of an afterlife because He knew not everyone would live a comfortable one here on earth. It is up to us to fend for them and yet they still starve and die daily; but God has something more for them and "the last will be first and the first will be last".
Yes, it is very easy to be atheistic when one has everything they need or desire here on this earth, but it is passing away and we all shall face our Creator one day and we will all have to bow before Him and tell of that life and the decisions we made. Not believing it does not mean it still will not happen, just as not believing in God does not disprove or expel Him. Live as you will, but know that your life will indeed summon one sentence or the other.
And even if hell is not eternal fire, an eternal separation from the God you will witness in all His glory, at that time, will indeed be a sentence of misery in the darkness without His light.