Free Will Baptists affirm the 66 books of the Protestant Bible — 39 Old Testament and 27 New Testament — as the complete and authoritative canon of Scripture. The Treatise of the Faith operates within this canonical framework, and the denomination rejects the deuterocanonical books (Apocrypha) that are included in Catholic and Orthodox Bibles.

The canon is understood as closed — no new books are to be added, and no revelation with the status of Scripture has been given since the apostolic age. This conviction undergirds the Free Will Baptist emphasis on Scripture as the ultimate authority and the rejection of ongoing prophetic revelation. While historical Christian writings (creeds, confessions, commentaries) may be studied and valued, only the 66 canonical books carry divine authority for doctrine and practice.

The free availability and accessibility of Scripture is emphasized in Free Will Baptist tradition. Every believer is encouraged to read the Bible for themselves and to understand its teaching. Pastors and teachers are called to guide the church in biblical understanding, but the primary authority rests with Scripture itself, open to all believers through the work of the Holy Spirit.