“For they {our Earthly fathers} indeed for a few days chastened us as seemed best to them, but He for our profit, that we may be partakers of His holiness. Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it” (Hebrews 12:10-11)
I can see what you mean, that perhaps people in the afterlife are chastened by the Lord so that they may increase in holiness. But, I dont really see holiness as a direct byproduct of being chastened. I see it more of an indirect byproduct.
Meditate on that passage and you’ll come to a better understanding of Latin spirituality, I think. It can be taken in the sense of God “getting His anger out on us”, but that is not the way the Latin tradition understands it. Rather, God gives us chastisement in order to keep us growing; we take up our Cross and become more united to Christ.
The “punishment”, in this sense, has to do with the unpleasant nature of this conformity with Christ, not necessarily with God having to enact a judgement (though God’s Justice is certainly present as well); Christ’s Glorification didn’t come pleasantly either, remember. The Latin tradition tends to emphasize this aspect a lot, perhaps more than any of the other Apostolic traditions, but doing so hardly makes it unApostolic. If anything I’d say it’s a necessary reminder of Apostolic Faith to the Church, just as other traditions have their own specialties and focuses that are truly Apostolic and enriching for us all.
This is why you’ll hear Latins speaking of “offering up” their sufferings to God, or thanking God for infirmities and unpleasantries in life. It’s part of the tradition that these difficulties are gifts from God that strengthen us and help us grow in Holiness, just as Christ was Glorified by the Cross. We even have mystic Saints in the Latin tradition who recommend turning away from even Spiritual delights, not in order to be morbid, but because 1 ) they are not the true substance of Grace, but rather a pleasant side-effect, 2 ) they can be misleading, because many things, even diabolic influences, can cause pleasant Spiritual feelings, and 3 ) Christ Himself denied them in accepting humiliation and death on the Cross, and we are most perfectly conformed to Him when we take on all that He took on; while He was perfectly God and not ever forsaken, He was still able to recite the Psalm that said “my God, my God, why have you forsaken me?” He was denying Himself the Spiritual pleasantry of His very Being in order to most perfectly confront evil.
Purgatory can be likened to the proccess after death by which the human soul turns from created pleasures and joys, and fully embraces God, just as we do with our penances and fastings on Earth. Fasting, for example, isn’t pleasant by any stretch (and is therefore a punishment, in the classic sense of the term meaning something that is unpleasant but which repairs), but it is part of our spiritual growth and leads to a much greater reward and happiness. Purgatory is kind of like a final fasting period of sorts.
On Merit: Mardukm has already ably dealt with the matter, but I’ll just add that merit is basically the Latin theological way of explaining that when we work with Grace, Grace increases. God gives us Grace, we do good works, we pray, ect, and Grace abounds within us more. It’s not an obligation on the part of God, but a natural outgrowth of our relationship with Him.
Both the initial gift of Grace and the increase are purely from God’s abundant Goodness and generosity, but there is a sense in which we work with the initial Gift as a means of increasing it, and that is called Merit in theological terms. An analogy would be the proper investment of received money, like Christ’s parable of the rich man who gave his servants money and one buried it while the other invested and returned with more than he had initially been given. Merit is the ever-increasing bounty of Grace that is tied to our (and the Saint’s) cooperation with God; a kind of personal and corporate theosis, to use a Greek term.
The theological terminology and approach isn’t necessarily present in the Byzantine tradition, but its practical application can be seen whenever we offer a Divine Liturgy on a deceased person’s behalf, with the knowledge that it helps to Sanctify them; that is an example of us applying our “merits” (cooperation with the Divine Grace through the Divine Liturgy) to another in need. Applying indulgences to a dead loved one works on a similar principle (and is found in Scripture, incidently, in Second Maccabees).
Hope that helps!
Peace and God bless!