Here are a couple of verses (among a group of related verses, Matthew 10:15, 11:21-24, Luke 10:12-14) that could indicate a chance for postmortem redemption.
Matthew 11:21"Woe to you, Chorazin! Woe to you, Bethsaida! For if the miracles had occurred in Tyre and Sidon which occurred in you, they would have repented long ago in sackcloth and ashes.”
Matthew 11:22 “Nevertheless I say to you, it will be more tolerable for Tyre and Sidon in {the} day of judgment than for you.”
Jesus is saying that Tyre and Sidon would have repented long ago if the miracles had occurred there. In addition, Jesus is saying that judgment day will be more tolerable for Tyre and Sidon, presumably because they did not have the benefit of witnessing the miracles.
Now, what does it mean that judgment day will be more tolerable? If the judgment is burning in hell for eternity, as hell is often depicted, how can anything about that be more tolerable? Are we to imagine that burning at a lesser temperature for eternity or that burning for a briefer time per day for eternity is more tolerable?
If suffering in hell, instead, comes through separation from God, then what possibly could be said to be more tolerable about judgment day if one is still going to be separated from God?
And more importantly, would God really condemn these people to hell in the first place, knowing they would have repented had they experienced the miracles?
Is it possible that more tolerable means that these people would be given a chance to repent sometime after they see God in all of His glory? That would be a more tolerable judgment day, and it would be compatible with the character of God as depicted in the Bible.
This possibility may also shed some light on the puzzling verses, 1 Peter 3:18-20.
1 Peter 3:18 For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
1 Peter 3:19 By which also he went and preached unto the spirits in prison;
1 Peter 3:20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
Here Jesus preaches to the spirits of those people who were not saved in the days of Noah. That they were not saved implies they were among the wicked. Why would Jesus have preached to these people who were destined for hell? Will they experience a more tolerable judgment, too? Does God know they, too, would have repented had they witnessed the miracles?