To better understand purgatory, the question to ask is not, “Was Jesus’ one sacrifice sufficient to atone for our sins?” It was and is, specifically regarding the eternal punishment due our sins.
Rather, we should first ask, “In saving us, does Jesus require our cooperation, including our detaching from the bad habits associated with our already forgiven sins—unhealthy attachments to ourselves and other persons and things, whom and which we have valued more highly than God, so that we can be truly fit for eternal communion with the Lord?” (See Rev. 21:17.)
We should also ask whether Scripture supports such detachment from already forgiven sins—i.e., doing penance for those sins, and whether any such penance unresolved on earth must be completed after our lives here on earth.
Forgiveness vs. Penance/Detachment
When a person commits a crime on earth, he can sincerely repent and receive God’s forgiveness. But he’ll still have to do penance for his wrongdoing. We don’t just let a criminal go free, even if we’re convinced he’s truly contrite. A perpetrator of a heinous crime can sincerely repent and receive forgiveness from God, but society still requires him to do his penance (e.g., life in prison without parole), and the government wouldn’t think of requiring the victim’s loved ones to authorize the criminal’s complete exemption from serving time for his crime.
Penance is where we get the term “penitentiary,” or prison. It’s contrary to logic that we on earth would have a standard of justice higher than our Lord Jesus Christ—that we would require penance for and (implicitly) detachment from our already forgiven sins, yet God would not.
If we do have a standard of justice higher than Jesus’ standard, then “once saved, always saved” (AKA eternal security) is ironically the ultimate plenary indulgence, because one could sin gravely unto death, and not repent and become detached from his disordered love of his sins (including already forgiven sins), and yet the Lord would be on the eternal hook to let him into heaven, given his one-time, allegedly irrevocable acceptance of his gift of salvation.
Some might counter that a true Christian wouldn’t gravely sin unto death. We should not be so presumptuous upon God’s mercy (see CCC 2091-2092), although the “once saved, always saved” doctrine would necessarily accommodate such presumption. More to the point, even if one has repented and received forgiveness, that doesn’t mean he is fully detached from the bad habits associated with his sins.
Don’t think so? Ask any wife whose husband has repented of his attachment to pornography yet still is prone to treating her like an object, given the lingering nature of his cultivated bad habit. Ditto for the wife who has been a compulsive liar, had a well-established anger problem, etc.
To reaffirm, viewing purgatory as a purification of our heart and character—a purification that extends beyond repentance for and forgiveness of our sins—makes the dogma a lot more understandable. Because everyone can see that detachment from bad habits and vices doesn’t necessarily accompany the repentance of and forgiveness for sins. Indeed, even if we’ve repented of all of our sins on earth, we can still have remaining attachments to our bad habits and related sins— persons and things of which we’ve made idols, including ourselves. Thus, further, the logic of purgatory.
Jesus on Purgatory
Jesus speaks of our need to do penance, distinguishing that penance from receiving forgiveness (see Matt. 5:23-27). In addition, St. Paul speaks of a person who is saved or forgiven yet still needs to be purified after death:
According to the commission of God given to me, like a skilled master builder I laid a foundation, and another man is building upon it. Let each man take care how he builds upon it. For no other foundation can any one lay than that which is laid, which is Jesus Christ. Now if any one builds on the foundation with gold, silver, precious stones, wood, hay, stubble—each man’s work will become manifest; for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each one has done. If the work which any man has built on the foundation survives, he will receive a reward. If any man’s work is burned up, he will suffer loss, though he himself will be saved, but only as through fire (1 Cor. 3:10-15).
The key verses are 12-15, and particularly 14-15 in light of the preceding. Paul clearly notes that some who are saved will receive a reward regarding their work and their choices on earth, a reward distinguished from their receiving the gift of eternal salvation. Paul also notes that although others will be saved, and for whom no reward is mentioned, they will still have to undergo purification, presumably because of their remaining attachment to or affection for their bad habits and vices. And it’s important to recognize that this purification takes place after “the Day”—i.e., after they’ve died and been judged by God.
The Church’s teaching on purgatory, and her related teaching of praying for the dead, has been consistent throughout Church history.
If the Church were wrong on purgatory, to say nothing of even more fundamental teachings like the Eucharist and the sacrifice of the Mass, then it would indicate that the gates of hell have prevailed against Christ’s Church for some fifteen hundred years, contrary to what Jesus promised (Matt. 16:18-19), until Martin Luther, John Calvin, et al. came along. Even then, they and their successors couldn’t agree on key doctrines—e.g., how we’re saved—indicating a further defeat, to one extent or another, of Christ and his Church.
The Church’s teaching on purgatory is also consistent with our Lord’s teaching in the Sermon on the Mount: “You . . . must be perfect, as your heavenly Father is perfect” (see Matt. 5:43-48).
True Love Is Reciprocal
Jesus’ plan of salvation requires that we be “all in”—that we personally account for the negative impact our actions have had in this world and on ourselves, for our unhealthy attachments to persons and things, and for which we have not done adequate penance.
This is the reality of bad habits. In purgatory, God mercifully purifies us of these unhealthy attachments so that we will be free to give every ounce of our love and devotion to the Lord.
In their zeal to emphasize God’s sovereignty (Calvin) and mercy (Luther), the early Protestant leaders forgot the basic reality that real love is a two-way street and thus calls for a response in kind—especially with Jesus, who will not simply overwhelm us with his grace, irrespective of a genuine free-will response (Calvin), or look the other way regarding our sins (Luther). No, Jesus wants to truly rehabilitate us by enabling us to love as he does—unconditionally and sacrificially. He does so through our self-denying and redemptive cooperation. As St. Augustine says so well, “God created us without us: but he did not will to save us without us” (CCC 1847).
Purgatory can be an uncomfortable reminder that salvation is not a one-and-done event, but a lifelong process in which our everyday personal choices definitely have an impact. This process undoubtedly begins on earth, which is why Jesus emphasizes that each of us must bear his cross on our journey to heaven (Matt. 16:24-27).