Who decided which books are in the Bible?

God is the author of Sacred Scripture, working through human authors whom He inspired (CCC 105-106). The Catholic Church did not create the Bible's authority, but discerned which writings belonged to the inspired canon entrusted by Christ to His Church.

Before there was a complete Bible. The first Christians received the Old Testament Scriptures and the teaching of the apostles. The New Testament books were written during the first century, but they did not arrive as one bound volume with an inspired table of contents. Individual Gospels and apostolic letters circulated among local churches and were read in worship. Some writings were quickly accepted everywhere, while others, such as Hebrews, James, Revelation, and Second Peter, were disputed in certain regions.

How the Church discerned the canon. Bishops considered whether a book came from the apostles or their close companions, agreed with the faith handed down from the apostles, and was widely received in the Church's worship. This discernment took place within Sacred Tradition under the guidance of the Holy Spirit. Scripture, Tradition, and the Church's teaching office belong together in God's plan (CCC 80-83, 95). The Church is called the pillar and foundation of truth (1 Tim 3:15), and Christians are commanded to hold fast to apostolic traditions received both orally and in writing (2 Thess 2:15).

When the list became clear. By the late fourth century, the Church had reached broad agreement on the twenty-seven New Testament books. The Synod of Rome in 382 and the councils of Hippo in 393 and Carthage in 397 and 419 gave canonical lists corresponding to the Catholic Bible. These lists included the deuterocanonical Old Testament books. The Council of Trent solemnly defined the canon in 1546 in response to Reformation disputes. The Catechism lists forty-six Old Testament books and twenty-seven New Testament books (CCC 120).

What this does not mean. No emperor, medieval pope, or single council suddenly invented the Bible. The canon developed through the Church's long reception and discernment. Later councils confirmed what had already been read, preached, and handed down in Catholic worship. A council's definition gives certainty about the canon, but the books are inspired because God inspired them.

When reading the Bible, receive it as the Word of God given through His Church. A Catholic Bible preserves the complete canon that the Church has received and proclaimed for centuries.