New World Encyclopedia:
"The rabbinic tradition draws a distinction between Sheol and
Gehenna or 'Gehinnom.' Originally, Judaism described life after death
as a bleak underworld named Sheol, which was known as the
common pit or grave of humanity. However, with the influence of Persian
thought and the passing of time, the notion of 'hell' crept into Jewish tradition
and became associated with the biblical word Gehinnom or Gei Hinnom (the
valley of Hinnom (Joshua 15:8, 18:16; II Kings 23:10; Jeremiah 7:31;
Nehemiah 11:30). This view of hell was allegedly imported into
Judaism from Zoroastrianism, and it appears to have supplanted the
earlier concept of Sheol (mentioned in Isaiah 38:18, Psalms 6:5 and Job
7:7-10).
"Jews who embraced this view of hell included the group known
as the Pharisees. The larger, dogmatically conservative Sadducees
maintained their belief in Sheol. While it was the Sadducees that
represented the Jewish religious majority it was the Pharisees who
best weathered Roman occupation, and their belief in Zoroaster's heaven
and hell was passed on to both Christianity and Islam.
"In subsequent centuries, rabbinic literature expounded on
Gehenna as a place (or state) where the wicked are temporarily
punished after death. The godly, meanwhile, await Judgment Day in
the bosom of Abraham. 'Gehenna' is sometimes translated as 'hell,' but
the Christian view of hell differs from the Jewish view of Gehenna."
