Is the Bible alone the rule of faith? What about Tradition?

What the Church teaches. "Sacred Tradition and Sacred Scripture form one sacred deposit of the word of God" (Dei Verbum 10; CCC 80-82). Both come from the same apostolic source, and the Magisterium, the teaching office of the pope and bishops, serves the Word by interpreting it authentically (CCC 85-87). Three legs of one stool.

The Bible does not teach sola scriptura. The verse most cited, 2 Timothy 3:16-17, says Scripture is "useful" and "inspired," which Catholics fully affirm; it does not say only Scripture. Meanwhile, St. Paul commands: "Hold fast to the traditions that you were taught, either by an oral statement or by a letter of ours" (2 Thess 2:15). And John ends his Gospel by saying the world could not contain the books needed to record everything Jesus did (Jn 21:25).

The Bible came from the Church. For the first few decades there was no New Testament; the apostles preached. The canon was discerned by the Church over centuries. A Christian in the year 150 could not practice sola scriptura because the table of contents did not exist yet. Scripture calls the Church, not the Bible, "the pillar and foundation of truth" (1 Tim 3:15).

The practical problem. Scripture needs interpretation: "there are some things hard to understand that the ignorant and unstable distort" (2 Pet 3:16). The Ethiopian eunuch asked, "How can I understand unless someone instructs me?" (Acts 8:31). Without a living authority, sincere readers reach opposite conclusions, which is why there are tens of thousands of Protestant denominations.

Catholics love the Bible. The Church reads more Scripture at Mass in three years than most congregations hear in a decade. Tradition is not an alternative to the Bible. It is the living memory of the community that wrote it.