Hi Zarthan,
Before Jesus rose from the dead and entered heaven, no one was permitted to enter heaven because of the stain of original sin. Jesus is our redeemer and the bridge between man and God now, where we now have the Sacrament of baptism that cleanses us and our faith that saves us in Jesus Christ.
Before Jesus the dead “slept” in Sheol, a netherworld of the dead that was divided into two “places” - paradise and hades. Paradise, recall, is where Jesus said to the thief on the cross that He and the thief would be - not heaven. Paradise is where the OT saints who were going to go to heaven “slept” (or resided) and awaited Christ. Hades was the place where the unsaved were going to hell.
This “paradise” in Sheol was also described as “Abraham’s bosom” and this is the place that was described in Jesus’ parable of the rich man and the poor man (Lazarus), - not heaven and not hell, and not purgatory, really, but Sheol.
This is the place that Jesus went to release those spirits in prison - the place of the dead, and preached the good news to them so they may be saved.
Once Jesus rose from dead and then later ascended into heaven, all those souls who were ‘saved’ were allowed into heaven. As Scripture tells us, Jesus is the firstfruits of heaven, and no one could enter until He did for He ‘ransomed’ (redeemed) us and paid the price for our remittance of sins.
blessings,
