The Catholic Church and her members know that Scripture is important, but it is not the only way God’s Revelation has been passed down to us. “Sola Scriptura” is a Latin phrase meaning, “only Scripture” or “Scripture alone.” Christians who subscribe to sola Scriptura believe that the Bible is the only authoritative source of revelation.
The Church understands that God’s Revelation has come down to us in ways that are not limited to the Bible. St. John (John 21:25) writes that Scripture does not contain everything about Christ. Besides the Bible, matters of faith revealed to us by God have also been passed down through Tradition. Tradition is the living transmission of the message of the Gospel in the Church.
For example, many of our beliefs about Mary are not explicitly taught in the Bible but are implicitly present; they have been passed down beginning at the time of the Apostles and have been consistently reflected in the prayer and belief of the Church.
Authoritative teaching continues today through the bishops, who are the successors of the Apostles. Both Scripture and Tradition come to us from the revelation of God in Jesus Christ and neither is complete without the other.