“And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him. And the Lord said unto Cain, Where is Abel thy brother? And he said I know not: Am I my brother's keeper?…..And now thou art cursed from the earth, which hath opened her mouth to receive thy brother's blood from thy hand……And Cain went out from the presence of the Lord, and dwelt in the land of Nod, on the east of Eden.” Genesis 4:8, 9,11,16 (Concordia Bible)
Note that there is no mention of a tormenting hell in these scriptures or in any subsequent references to Cain.
The word hell–sheol in Hebrew and hades in Greek–signifies hidden, extinguished or obscure–the condition or state of death. Both the good and the bad go to the condition of oblivion, where they await the resurrection of the dead, as guaranteed by the death of Christ on the cross. “For since death came by man, by man came also the resurrection of the dead; as all die in Adam, so shall all be made alive in Christ.” 1 Corinthians 15:21, 22 (Moffatt)
Eternal torment was never the Jewish belief. However, the Greek philosophers believed in the immortal soul and this belief was adopted by the Catholic church. Recognizing that the wicked could not be rewarded with heaven, the Catholic Church developed the doctrine of punishment in hell and purgatory. Then the doctrine of hell was extended into Protestant creeds.
“Whatsoever thy hand findeth to do, do it with thy might; for there is no work, nor device, nor knowledge, nor wisdom, in the grave (sheol) whither thou goest.” Ecclesiastes 9:10 (KJV)