Dear Chantel:

I am sorry that your Catholic education failed you. This is a huge problem, especially in the United States.

Grave sins must be brought to the Sacrament of Confession. Purgatory will not purge grave sins. If one dies with grave sins on their soul they will go to hell.

Purgatory is a place to purge the residue of grave sin, not the grave sin itself, and also any outstanding venial sins. The following analogy is how I usually explain this:

If I purposesly throw a rock through your window I have committed a sin. I can ask God for forgiveness and He forgives me on account of the Cross. While both you and God may forgive me, the window is still broken and must be fixed. Since I broke the window it is my responsibility to fix the window.

Purgatory is a place where all the broken windows that I did not get fixed during my life gets purged from my soul. The sin was forgiven but the "consequences of sin" (the broken window) remains until such time I fix the window in this life or have it purged in Purgatory.

1 Corinthians 3:15 is a perfect definition of purgatory. St.Paul states: "If any man's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire."

Those in Purgatory are saved, but the bad works and outstanding "consequences" of sin are burned up in fire (purged).

To get to heaven we must not only be in a state of grace, but also perfectly holy. There cannot be any residue of sin or bad works on our account if we are to be perfectly holy. The state of grace makes us like gold, but gold ore that has impurities. When gold is purged in fire the impurities come out and what is left is pure gold.

This is what Purgatory does for us. We are made gold ore by the Cross, but the impurities must be purged away, either through the attainment of holiness in this life (like the Saints), or through Purgatory.

On your question about private confession and confession to a priest, it is not the same thing. Venial sin may be confessed privately to God; but grave sin MUST be brought to the Sacrament of Confession with a priest.

As for sins that have been forgotten, it is appropriate to add in your list of sins when confessing to a priest words such as: "...For these, and all my other sins which I cannot now remember, I am heartily sorry, firmly intend to do better, most humbly ask forgiveness..."

Making this kind of confession will "cover" all the sins you have forgotten. If at a later date you remember a grave sin, then go ahead and bring that to confession at that time.

Here is the Catehcism teaching on Purgatory:

III. THE FINAL PURIFICATION, OR PURGATORY

1030 All who die in God's grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of heaven.

1031 The Church gives the name Purgatory to this final purification of the elect, which is entirely different from the punishment of the damned. The Church formulated her doctrine of faith on Purgatory especially at the Councils of Florence and Trent. The tradition of the Church, by reference to certain texts of Scripture, speaks of a cleansing fire:

As for certain lesser faults, we must believe that, before the Final Judgment, there is a purifying fire. He who is truth says that whoever utters blasphemy against the Holy Spirit will be pardoned neither in this age nor in the age to come. From this sentence we understand that certain offenses can be forgiven in this age, but certain others in the age to come.

1032 This teaching is also based on the practice of prayer for the dead, already mentioned in Sacred Scripture: "Therefore Judas Maccabeus] made atonement for the dead, that they might be delivered from their sin." From the beginning the Church has honored the memory of the dead and offered prayers in suffrage for them, above all the Eucharistic sacrifice, so that, thus purified, they may attain the beatific vision of God. The Church also commends almsgiving, indulgences, and works of penance undertaken on behalf of the dead:

Let us help and commemorate them. If Job's sons were purified by their father's sacrifice, why would we doubt that our offerings for the dead bring them some consolation? Let us not hesitate to help those who have died and to offer our prayers for them.

 I hope this helps you understand Purgatory a little bit.

God Bless,
Bro. Ignatius Mary