Gehenna
The earliest Christian writers seem to have believed that only those who have been welldoers in this world-age would ever reach union with God, while wrongdoers would hereafter experience only distress.
I believe that God will save all selves, that "the wrath to come", even if it really will be a future experience rather than an interpretation of present experience, will be remedial, for I believe that all God's works tend to the flourishing of his world, and I see no benefit in inflicting distress merely because it is deserved.
I cannot doubt that They whom you deplore
Are glorified; or, if they sleep, shall wake
From sleep, and dwell with God in endless love.
Hope, -- below this, consists not with belief
In mercy carried infinite degrees
Beyond the tenderness of human hearts:
Hope, -- below this, consists not with belief
In perfect Wisdom, guiding mightiest Power,
That finds no limits but its own pure Will.
Wordsworth, The Excursion Book 4
Either way, better to do right now, for the refining process will be more distressing if delayed until the future world-age.