From Haring Felipe to my sister in the Christian faith, I would like to explain to you the doctrine of purgatory and how we can demonstrate from the Bible the reality of its existence.
Judgement after death
After death, Heb 9:27 says, it’s judgment. Rev 21:27 says that “Nothing unclean can enter Heaven”. What makes someone unclean? Sin or sinfulness. But St. John said that there are two kinds of Sins…Every kind of wrongdoing is sin, but not all sin leads to death (1Jn 5:16-17). The sin that leads to death is what, we call “mortal sin”. The sin that does not lead to death we, call “venial sin”. “Death” here refers to second death which is HELL (Rev 21:8). He, therefore, is inferring that your unrepented venial sin stains the soul. Your unclean soul is unfit for heaven but it will not lead you to “second death” either. Thus, those lesser stains shall be removed from you before entering into the Glory of God. Who will remove it? God! By his mercy and grace, He will purify you by purging you who is tainted with venial sins.
St Paul reveals what happen after death, “If any man’s work burn, he shall suffer loss; but he himself shall be saved, yet so as by fire” (1Cor 3:15). It says you will be saved as if through fire. This process of purification or purging through fire is what we call “Purgatory”. Those in it, therefore, are already saved and destined for Heaven.
Praying for those who passed away
Now why pray for those in purgatory? Because St John said so, …Pray for Him and God will give life to your brother (1Jn5:16). Are these words only for the living? No, because in the eyes of God there is no distinction between living saint and dead saint. He said, “I am the God of Abraham, the God of Isaac, and the God of Jacob? He is God, not of the dead but of the living” (Mt 22:32). It means that Abraham who is long time dead is alive in God. Hence St. Paul reasoned, death cannot separate us from the love of God (Rom 8:35) therefore everyone who believe in Christ is a member of the Body of Christ, the Church, (Eph 5;23; 1Cor12:12). Your membership in the body of Christ does not cease after you die. So those who die in friendship of God are still included. We pray for them because we pray for each other being members of the body of Christ.
Those in Purgatory are members of the mystical body of Christ – The Church
St. Paul said, “But now there are many members indeed, yet one body. And the eye cannot say to the hand: I need not thy help; nor again the head to the feet: I have no need of you.” (1Cor 20-21). He continued by saying, “God himself arranged the body in this way, giving more honor to those parts that need it, so that the body may not be divided, but rather each member may care for the others”. Catholics pray for those who passed away because we care for them. And they (the dead in the process of purification) are saying to the other part of the body of Christ who are still living “we need you”.
Lastly, purgatory is not a third and/or final place of destination after life, because those who are in purgatory are sure of heaven – their real destination. It is not lasting because in the last judgement, there will only be Heaven and Hell (Mt 25:31ff).
Hope I make it clear for you. Glory be to the Father, Son and Holy Spirit! Amen.