‍How can the pope be infallible when some popes were terrible sinners?

  Gary Hoge  ·  November 5, 2026

‍Well, some certainly were. Pope Alexander VI (1492–1503) was widely accused of buying his way into the papacy, and he fathered several children by his mistresses. Pope Stephen VI (896–897) had his predecessor, Pope Formosus, exhumed and put on “trial.” Not surprisingly, Formosus lost, and his body was eventually thrown into the Tiber River. Stephen himself was strangled to death a few months later.

‍There’s no question that the Church has had some corrupt, worldly popes in its long history. So how can Catholics possibly claim that the pope is infallible?

‍Because there’s a difference between being infallible (being protected from error when teaching under certain conditions) and being impeccable (being incapable of sinning). Catholics have never claimed that popes are incapable of sinning, and history certainly bears that out.

‍Even the holiest pope is capable of sinning, and even the most sinful pope can be prevented by God from teaching error.

‍There’s actually a biblical precedent for God speaking through an unworthy religious leader. Caiaphas, the high priest who participated in the plot against Jesus, unwittingly prophesied that Jesus would die for the nation. John tells us that he spoke prophetically because he was high priest that year (John 11:49–52).

‍Think about that. Caiaphas was involved in the conspiracy that led to Jesus’ crucifixion, yet God used him to proclaim a truth about Jesus’ death. And John specifically connected his prophecy with the office he held, not with his personal holiness.

‍Clearly, God can use a man to communicate divine truth without endorsing the man’s personal conduct.

‍Catholics believe that something similar happens when the pope teaches infallibly. Under certain specific circumstances, the Holy Spirit prevents him from teaching error, regardless of his personal holiness. That doesn’t mean everything he says is infallible. This protection applies only when, acting as supreme teacher of the universal Church, he definitively proclaims a doctrine of faith or morals to be held by the whole Church.

‍And there’s an important distinction between infallibility and divine inspiration. The authors of Scripture wrote under inspiration, so that what they wrote was both genuinely their own work and what God wanted committed to writing. The pope isn’t inspired in that way. He gets his knowledge the same way we all do: through prayer, study, and consultation with others. Infallibility doesn’t mean the Holy Spirit whispers the right answer into the pope’s ear.

‍It means that when the pope exercises his authority to define a doctrine infallibly, the Holy Spirit prevents him from teaching error—even if he has to keep the pope’s mouth shut.

‍And the pope is protected—or rather, we are protected—not because the pope deserves special treatment, but because God wants the Gospel to be preserved. When controversies arise and questions of faith or morals must be definitively settled, Christ hasn’t left his Church with nothing more than one man’s opinion.

‍He’s given his Church the assurance that its definitive teaching will be protected from error.

‍So pointing to the sins of individual popes doesn’t disprove papal infallibility. It merely demonstrates something Catholics have never denied: popes are human beings, and some of them have been very sinful human beings indeed.