How can an omnibenevolent God justify eternal damnation for finite sins?

God is all good as his attributes describe. So how can an all good God justify eternal punishment for X amount of time spent on the temporal/material plane. This seems to oppose his trait of a benevolent and merciful god. This I feel ties in with the fact that God created men as men are contingent beings God due to his omniscience knows ahead of time that they will sin. Then send them to a Hell that he created. I know that we have free will and can choose our ultimate fate and that is good but is it benevolent to allow a being to come into existence when the outcome is known. Then send him to a Hell that he created for eternal punishment. Thank You for your time.