Purgatory removes dross. Every soul not to spend their eternity in hell passes through it. Those sentenced to hell, are burned up and their consciousness relegated to hell and its continued burning for eternity. Since God is holy and pure, only that which is like Him may enter into His peace. That is why Jesus said: " be holy as your Father in Heaven is holy". The first pope of the Roman Church reiterated that
1 Peter 1:15-16
But just as He who called you is holy, so be holy in all you do, / for it is written: “Be holy, because I am holy.”
Purgatory as I said, removes dross, but most importantly to note, purgatory removes unknown sin, not deliberate sin. I say that because someone in here mentioned mortal sin. That is not what purgatory is for. Hell is for mortal sin. Both of my stances are confirmed by holy scripture.
Saint Paul addresses the manner in which purgatory is applied. See, all not in mortal sin pass through the holy fire to God's peace. Depending on your state at death, determines its effect. Saint Paul explains it like this...........
1 Corinthians 3:
10According to the grace of God given to me, like a skilled master builder I laid a foundation, and someone else is building upon it.
Let each one take care how he builds upon it. 11For no one can lay a foundation other than that which is laid, which is Jesus Christ.
12Now if anyone builds on the foundation with
gold, silver, precious stones, wood, hay, straw—( St. Paul uses tangible examples in allegory for the state of the soul. Depending on your state determines the holy fire's effect.) 13each one’s work will become manifest,
for the Day (The Day you die) will disclose it, because it will be
revealed by fire, and the fire will test what sort of work each one has done. 14If the work that anyone has built on the foundation survives, he will receive a reward.
15If anyone’s work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.
As those baptized in Christ, building upon the foundation, that which we do and teach must adjoin to the foundation, if not it is burned up.
Depending on your condition determines amount of time. Some have much dross, some not as much, those who are not gold, silver or precious gems, get discarded. For a king does not retain wood, hay or straw. Like a gold/silversmith, the Lord pulls the soul out at the right time. He knows exactly when and we get a glimpse of how it works with an earthly silversmith. He knows when the silver is ready to pull when he sees his own reflection in the silver, gold as well. If left too long all is lost. Only silver, gold and precious gems can be snatched from the fire. The rest is discarded ( wood, hay, straw are cast to hell.) For a king has no use for such states. Precious gems pass through like passing through warm milk. That is simple to understand by seeing how both silver and gold respond to the same fire as precious gems here on earth. What melts them does not melt precious gems. Mother Mary also taught that some souls are blessed to do their purgatory on earth. I think she is speaking to the end of the age Elect who will be here to see the return of Christ upon the clouds of heaven. Like their Heavenly Mother, they are transformed in a moment, in a twinkling of an eye. It is an instant death and resurrection at the end of time at the Second Coming of Christ. It is not a pre-trib, mid-trib rapture as taught by Protestants, it is at the second coming of Christ. Some will be on the earth alive at His return.
1 Corinthians 15:
51Listen, I tell you a mystery: We will not all sleep, but we will all be changed—
52in an instant, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed.
53For the perishable must be clothed with the imperishable, and the mortal with immortality.
54When the perishable has been clothed with the imperishable and the mortal with immortality, then the saying that is written will come to pass: “Death has been swallowed up in victory.”
55“Where, O Death, is your victory?
Where, O Death, is your sting?”
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56The sting of death is sin, and the power of sin is the law.
57But thanks be to God, who gives us the victory through our Lord Jesus Christ!
58Therefore, my beloved brothers, be steadfast and immovable. Always excel in the work of the Lord, because you know that your labor in the Lord is not in vain.
Back to Purgatory ........Depending on your state determines the effect of God's holy fire. Mother Mary too speaks of venial sin, she has said- "There are those who sin and those who love sin". Venial sin is not deliberate sin, it is not- making a practice of sin, but a hate of sin, mortal sin is- making a practice of sin and a love for it. This is addressed too in holy scripture.
1 John 5: 1
That You May Know
13I write these things to you who believe in the name of the Son of God, that you may know that you have eternal life.
14And this is the confidence that we have toward him, that if we ask anything according to his will he hears us.
15And if we know that he hears us in whatever we ask, we know that we have the requests that we have asked of him.
Concerning Prayer:
16If anyone sees his brother committing a sin not leading to death
(Venial sin), he shall ask, and God will give him life—to those who commit sins that do not lead to death. There is sin that leads to death
(Mortal sin); I do not say that one should pray for that. 17All wrongdoing is sin,
but there is sin that does not lead to death.
Mortal- deadly, lethal fatal.........Hence, Mortal sin.
The Elect are taught there is sin that we are not required to pray for. So, when asked by our Mother to pray for souls in purgatory, we are not praying for those with Mortal Sin but rather Venial Sin. The Holy Spirit lets us know when applicable or not applicable. I have experienced non-applicable attempts. It feels like a mental block that does not allow for the touching of that person. I understand why too. Mortal sin is always deliberate; it stems from continual practice with no recourse. The weight would be too great for a child of God to help with. It is loved; the sin is loved, practiced and cannot be moved through prayer. God does not expect us to lift such a dead weight. I know many in mortal sin that certain of the Church require prayer for. My Heavenly Father says He does not want me to pray for some people.