Protestant apologists Norman Geisler and Ralph MacKenzie argue that the Catholic dogma of purgatory “in effect denies the all-sufficiency of Christ’s atoning death.” They quote biblical passages that speak of the sufficient nature of Christ’s work on the cross (John 17:4, 19:30; Heb. 10:14) and conclude, “To affirm that we must suffer for our own sins is the ultimate insult to Christ’s atoning sacrifice” (emphasis added).
Geisler and MacKenzie object to the idea that Christians experience some negative consequences for their sins. But they don’t explain why this is an insult to Christ’s atoning sacrifice. Others have tried, suggesting, for example, that the suffering in purgatory atones for the eternal punishment of sin, something only Christ can do. Still others have said that suffering for our sins in purgatory contradicts the sufficiency of Christ’s work on the cross because Christ’s death makes it unnecessary for Christians ever to suffer for their sins.
Does either theory have any merit?
Let’s start with the first one: the sufferings in purgatory supposedly atone for the eternal punishment of sin.
People who believe this are simply mistaken as to what the Catholic Church teaches about purgatory and atonement. Purgatory has to do with freeing us from the “temporal punishment of sin” (CCC 1472), not eternal punishment. Purgatory is a final purification of “the elect” (CCC 1031), those for whom eternal punishment has already been remitted by Christ’s atoning death.
The soul in purgatory is on its way to heaven, having already received the grace of salvation: fruit of the sufficient work of Christ on the cross. Purgatory is merely for the sake of making up for temporal consequences due to sin that remain after death.
Let’s now turn to the second reason why some people have suggested that purgatory undermines the sufficiency of Christ’s death on the cross: Christ’s death on the cross makes it unnecessary for Christians ever to suffer for their sins.
This belief doesn’t match up with the biblical data. Consider, for example, 1 Corinthians 3:11-15, where Paul describes how the works of a Christian are being tested:
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, straw—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.
This is a go-to passage for many Catholics in support of purgatory. But that aside, for our present purposes it at least portrays a Christian undergoing some form of suffering on account of bad works performed.
In this passage, Paul is clearly talking about a Christian (building on the foundation of Jesus). The “wood,” “hay,” and “straw” that are burned up represent the bad works (or sins) for which the Christian suffers “loss.” That the Christian will be saved “only as through fire” suggests that Christians will experience negative consequences for their sins.
We could also look at Hebrews 12:6, 10:
The Lord disciplines him whom he loves, and chastises every son whom he receives. . . . [He] disciplines us for our good, that we may share his holiness.
Notice that God chastises “every son whom he receives”—that’s to say, God disciplines Christians. But being “chastised” involves some sort of suffering for bad behavior. The Greek word for “chastise,” mastigoō, literally means to “lash,” “whip,” “flog,” or “scourge” for the sake of punishment. Therefore, God wills that Christians suffer for their sins.
The author of Hebrews also tells us the end to which such suffering is ordered: “for our good, that we may share his holiness.” So God doesn’t punish his children merely to reform external behavior but for conformity to his holiness. He chastises us so that we may become holy like him.
As in 1 Corinthians, we have a case of a Christian suffering for sins. Hebrews adds the end to which the suffering is ordered: sanctification. For the author of Hebrews, then, a Christian suffering for sins in order to be sanctified and the sufficient work of Christ on the cross are not mutually exclusive.
In fact, it’s because of Christ’s sacrifice for us that we can be sanctified (made holy) through our suffering in the first place. Without Christ’s death on the cross, our suffering for past sins would be to no avail.
And just as Christ’s death on the cross makes sanctification through suffering possible in this life, so too it makes possible our final sanctification in the next. As Jimmy Akin puts it, “His [Jesus] sufferings paid the price for us to be sanctified, and his sufferings paid the price for the whole of our sanctification—both the initial and final parts.”
Purgatory doesn’t contradict the sufficiency of Christ’s death on the cross. It depends on it.