According to Catholic Answers Tract about
Purgatory,
The Catechism of the Catholic Church defines purgatory as a “purification, so as to achieve the holiness necessary to enter the joy of heaven,” which is experienced by those “who die in God’s grace and friendship, but still imperfectly purified” (CCC 1030). It notes that “this final purification of the elect . . . is entirely different from the punishment of the damned” (CCC 1031).
The purification is necessary because, as Scripture teaches, nothing unclean will enter the presence of God in heaven (Rev. 21:27) and, while we may die with our mortal sins forgiven, there can still be many impurities in us, specifically venial sins and the temporal punishment due to sins already forgiven.
In the section of
Nothing Unclean,
Purgatory makes sense because there is a requirement that a soul not just be declared to be clean, but actually be clean, before a man may enter into eternal life. After all, if a guilty soul is merely “covered,” if its sinful state still exists but is officially ignored, then it is still a guilty soul. It is still unclean.
Catholic theology takes seriously the notion that “nothing unclean shall enter heaven.” From this it is inferred that a less than cleansed soul, even if “covered,” remains a dirty soul and isn’t fit for heaven.
It needs to be cleansed or “purged” of its remaining imperfections. The cleansing occurs in purgatory. Indeed, the necessity of the purging is taught in other passages of Scripture, such as 2 Thessalonians 2:13,
which declares that God chose us “to be saved through sanctification by the Spirit.” Sanctification is thus not an option, something that may or may not happen before one gets into heaven. It is an absolute requirement, as Hebrews 12:14 states that we must strive “for the holiness without which no one will see the Lord.”
Justice demands retribution for wrongs so it can be inferred that, though Purgatory is not Hell, it is still a place where suffering can exist. If you look into
St. Mary Faustina Kowalska’s diary, here’s an excerpt of from what she described about Purgatory:
I saw the Guardian Angel who ordered me to follow it. In one moment
I found myself in a foggy place, invaded by fire and an enormous crowd of suffering souls. These souls prayed with great fervour, but without effectiveness for themselves: only we can help them. The flames burning them did not touch me.
My Guardian Angel did not leave me alone a single moment. And I asked those souls what their greatest torment was. Unanimously they answered me that their greatest torment is the burning desire of God. I saw Our Lady who was visiting the souls of the Purgatory. The souls call Mary “Star of the Sea”. She brings them refreshing.
I would have wanted to talk longer with them, but my Guardian Angel made me to go out. And we went out of the door of that
prison of pain. I heard inside me a voice saying: “My Mercy does not want this, but justice does.”
From that time I have had more tighten links with the suffering souls of the Purgatory.