Is the Bible the only source of divine revelation for Catholics?

No. Catholics believe divine revelation comes to us through both Sacred Scripture and Sacred Tradition, which together form a single deposit of faith entrusted to the Church. The Bible is not self-interpreting apart from the living Tradition and Magisterium that first produced it and safeguard its right understanding (CCC 80-82).

The Catholic Church teaches that divine revelation is transmitted through two inseparable modes: Sacred Scripture and Sacred Tradition, both flowing from the same divine source and both to be accepted with equal reverence (CCC 80-82). This differs from the Protestant principle of sola scriptura, the belief that Scripture alone is the sufficient rule of faith.

The Bible itself was written, compiled, and canonized within the living Tradition of the Church before it was ever bound into one book. The Church did not receive her faith from a book; rather, the book emerged from the Church's apostolic faith and worship.

The Scriptural Basis for Tradition

St. Paul explicitly commands the Thessalonians to hold fast to teachings received both by word of mouth and by letter: 'Therefore, brethren, stand fast; and hold the traditions which you have learned, whether by word, or by our epistle' (2 Thessalonians 2:15). He tells Timothy to entrust what he has heard to faithful men who will teach others also (2 Timothy 2:2), describing an oral chain of transmission distinct from, yet harmonious with, written Scripture.

St. John acknowledges that not everything Christ did and taught was recorded: 'many other things also which Jesus did, which, if they were written every one, the world itself, I think, would not be able to contain the books that should be written' (John 21:25). And St. Paul calls the Church herself, not a book, 'the pillar and ground of the truth' (1 Timothy 3:15).

Scripture, Tradition, and the Magisterium Together

The Catechism explains that Sacred Tradition and Sacred Scripture make up a single sacred deposit of the Word of God, entrusted to the Church, and that both must be accepted and honored with equal sentiments of devotion and reverence (CCC 82). Neither Scripture nor Tradition can stand alone; they flow from the same divine wellspring and together form one thing, moving toward the same end (CCC 80).

This deposit is not left to private interpretation. The task of authentically interpreting the Word of God, whether written or handed down, belongs to the living teaching office of the Church alone, the Magisterium, which serves the Word rather than standing above it (CCC 85-87, 95). This is why St. Peter warns that no prophecy of Scripture is a matter of private interpretation, since prophecy never came by the will of man but by men moved by the Holy Ghost (2 Peter 1:20-21).

A Charitable Word to Other Traditions

Many Christian communities that hold to sola scriptura share the Catholic Church's deep love and reverence for the Bible as inspired and inerrant. The Catholic difference is not a lesser esteem for Scripture, but the conviction, grounded in the Bible's own witness and in apostolic history, that the Holy Spirit also guides the Church through a living Tradition and teaching authority that safeguard the true meaning of the written Word across every generation.