The belief in Hell is useful as an incentive not to sin. Once a sinner has died, torturing him serves no useful purpose, so there is no reason for a benevolent God to go through with it. If it is still possible for the sinner to reform and be saved he should be given another chance, as portrayed by C.S. Lewis in The Great Divorce. If he is a hopeless case, he can be painlessly removed from existence.
The obvious explanation of the available evidence, the explanation consistent with both the text and divine benevolence, is that scriptural references to Hell are a strategic lie. I do not know if there is evidence in scripture that God sometimes lies, but I do not see how there could be evidence that he never does.