Scripture's Authority from God: Westminster Confession 1.4-5

We should believe what the Bible teaches, and do what it says, because it is the Word of God. The Church testifies that the Bible is God's Word, and so it reverences it and submits to it The Scriptures themselves were written by prophets whose prophecies came true and Apostles who did the miraculous signs of an Apostle. Many valid arguments support the Bible's own testimony of itself as being God's Word. For example, despite being written by forty authors over a period of 1500 years in two different languages., it consistently teaches the same truths about God and about man. Nevertheless, by themselves, these arguments will not persuade prejudiced sinners. Only the Holy Spirit can open blind eyes.