So, having let some other things cool down a bit, back to this thread then.
There is some dispute among purgatorial universalists over what exactly purgatory involves, but the basic idea is that God doesn’t punish anyone except those who impenitently hold to their sin(s).
As I understand it, this involves several things first:
1.) More exposure to the Holy Spirit, Whose function is (among other things) to bring truth to people immanently. A number of non-universalists, both Eastern and Western, recognize the immanent presence of the Holy Spirit as God the consuming fire, and so actually agree that Gehenna (during or after hades/sheol) will involve this, leading to ECT or anni. We would differ subtly but crucially on the purpose of the Holy Spirit, which is why I put the phraseology as “bring people to truth”, not merely convict people about sin (although that, too): bringing people to truth ultimately fails if they don’t eventually drink the truth and become thoroughly (if dependently and subordinately) true themselves. A conviction of sin which finally results in anything less than that, involves a failure or else no actual intention to bring people to truth. (In short, Arm or Calv soteriologies respectively.)
This is a corollary of my understanding of trinitarian theism, which involves the Persons of God acting foundationally to all reality in fulfilling fair-togetherness between persons (first and self-existently between the Persons of God, and then subsequently among created persons, with each other and with the Persons of God). In the economy of the Trinity, the Spirit is the first and ontologically primary gift given by God: the gift of the Person of God given by God to persons (first and foremost given by the Father to the Son and by the Son to the Father). If God (in all Three Persons) gives the Spirit in increasingly fuller fashions to created persons, He’s working in consistence with His own continuing eternal self-existence. To do anything less or other (allowing of course for variances in how God goes about doing it), would be to act inconsistently with His own self-existence, leading to the non-existence of God and of all other reality.
While not every theologian everywhere works that out, I don’t think this is especially controversial (e.g. God the independent self-existent ground of all reality must and shall keep on being God or all reality is screwed, or rather we wouldn’t be here discussing the theoretical possibility of God acting against His own self-existence if He ever did do that); but accounting for it makes a big difference in how I regard positive justice, thus also in how I regard punishment of sinners for sin: the goal of punishment cannot run contrary to the positive function of justice in God’s own self-existent foundational reality upon which all reality depends for existence at all. To propose otherwise about God would be to propose a schism in the functional intentions (and thus in the self-consistent eternal reality) of the Trinity; to propose otherwise about ourselves would be at best to run contrary to the intentions of God (if perhaps inadvertently).
Anyway, on this concept God the Holy Spirit (sent by the Father and the Son, and proceeding ontologically from both if the filioque is true) is already working to some degree in every person (which is why any person is even a person at all; which is also why any sin is an abuse of the grace of God and even at bottom a sin against the Holy Spirit) toward this goal of fulfilling fair-togetherness among persons. When we sin we act against that purpose, but our unfaithfulness does not void God’s faithfulness and intentions. Sooner or later God increases the immanent presence of the Holy Spirit in each of us. This doesn’t automatically make us not sin, but it leads to an increased clarity about what is and is not righteousness (fair-togetherness, dikaiosunê), leading to increasing uncomfort insofar as we persist in insisting on sinning anyway.
Again, I don’t think this is especially controversial even among Calvinists, who ought to recognize this as a description of how God goes about convicting, converting, regenerating and justifying (making fair, making just) those whom He intends to save from sin. We don’t earn God’s salvation of us by converting; we convert because God is in the process of saving us from our sins and so empowers us to respond to Him (while leaving us some leeway about how long we may choose to hold out against Him, which from His omniscient perspective He already knows our choices about, originally creating His designs of history in His authoritative allowance of our choices).
What Calvs would controvert about this mainly is the scope of God’s action: the Arminianistic scope of everyone, not merely a selection. (What Arminians would controvert about this is the original persistence by God: Kaths agree with Calvs that God doesn’t have to be convinced to keep at it until He succeeds, much less convinced to start doing it in the first place.)
2.) Any illness or similar condition hampering cognition of righteousness must be removed. Presumably this would be done during the general resurrection, but God accomplishes some of it now in this life (sometimes by direct healing miracle).
3.) Any intentional baneful influence must also be removed.
Once those conditions are met, sin becomes nothing other than direct rebellion against the fulfillment of fair-togetherness between persons, and God punishes appropriately: that which is past can be pardoned, that which was accidental will be excused, but that which the person refuses to come out of must be punished.
Even then, the punishment may be very light; I expect most people will only need what amounts to a stern lecture or demonstration of disapproval. But the only people who actually need to fear the wrath of God are the people who insist on continuing to do what they themselves perceive (by the grace of the Holy Spirit) to be unjust.
To be convinced that one is of the special elect, in a Calvinistic sense, would of course relieve fear of being hopelessly punished by God – although so does being convinced that (proper) Katholicism, universalism, is true, that no one will be hopelessly punished by God (and the special elect are elected to be the leaders in cooperating with God in bringing the gospel to other people: elected not for their own sake but for the sake of other people, to be a light to the world, though subordinate lights under the Light Who is enlightening every man who is coming into the world).
But unless the Calvinist dismisses or ignores the several scriptural testimonies to the effect that God (even after the sacrifice of Christ) punishes those whom He intends to inherit when they misbehave (for example the testimony of Hebrews 12), Calvinism doesn’t, or anyway shouldn’t, provide total relief from the fear of every possible wrath of God. Until a person is thoroughly regenerated, we still should fear being chastised by God, not with a hopeless fear, but with either an improper fear of having to give up our sin (which is the natural reaction to the discipline of righteousness), or with a proper numinous fear of gratitude against our sin in favor of God’s foundational righteousness.
As C. S. Lewis used to say, referring to 1 John, perfect love may cast out fear, but so do many other things improperly; therefore we should not be content (and God will not let us rest content) with fear of chastisement being cast out by anything less than perfect love.
The alternative is not uniquely Calvinistic, but is one Calv variant suggesting that penal sub atonement means God does no wrath at all to the elect; matched and exceeded, in principle, by one Kath variant suggesting, usually also thanks to PSA theory, that God does no wrath at all to anyone. If what we call ultra-universalism is true, instead of purgatorial universalism, then of course that would be even more relief from fear of God. But even the no-wrath-at-all-for-elect variant of Calvinism still leaves over much fear for other people that they may be of the non-elect, and an utterly hopeless fear at that.
(To which, dovetailing with another recent topical thread, some Calvs would logically reply that such fear of God’s wrath for the non-elect is at best misguided, and will be adjusted eventually to rejoicing over their fate (whether ECT or anni), thus having no fear or grief at all for their sake. The only way to be relieved from all fear of God’s wrath, if Calvinism is true, is to take the position of the proponent Alex posted the paper about in this thread,, along with a variant of penal sub atonement theory which argues thereby that God will never act in any wrath against people He intends to save from sin. But not even all PSA proponents hold that as a result.)