Christ opened the gates of heaven for those in Abraham’s bosom when he descended into hell after his death.
Well, two words are translated as Hell in the NT, Hades and Gehenna. Gehenna appears to refer to the final place of judgement or Lake of Fire after the great White Throne Judgment. Hades appears to refer to the present Hell, where the unsaved go after death pending final judgment. Sheol is most often translated as “grave” but seem to generally refer to the land of the dead. The afterworld. It doesn’t really differentiate between separate places for the wicked and the righteous. However, the Pharisees of Jesus time certainly believed in a resurrection and some form of eternal life for those who kept the law.