1689:1.4. Authority of Scripture
4. The authority of the Holy Scriptures obligates belief in them. This authority does not depend on the testimony of any person or church but on God the author alone, who is truth itself. Therefore, the Scriptures are to be received because they are the Word of God.7
72 Peter 1:19–21; 2 Timothy 3:16; 1 Thessalonians 2:13; 1 John 5:9.
This section of The Confession sets Scripture as the highest authority. Well-intentioned Christian men and women may direct us to evidence. They may direct us to the testimony of the church, but ultimately Scripture testifies about itself. The Apostle Paul says in 2nd Timothy 3:16-17,
16 "All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for [a]instruction in righteousness, 17 that the man of God may be complete, thoroughly equipped for every good work." (NKJV)
The Scripture testifies about itself that it is the very word of God. Really to appeal to anything other than Scripture to assert Scripture's authority is to elevate that which you appeal to as an authority above the Scripture and this is a grave mistake. Christians confess that human authors penned the Bible, but they did so under the inspiration of the Holy Spirit. God was intimately involved in the process of recording His Words and He has preserved those Words all throughout church history. Theologian Sam Waldron asserts, "all of the words of the Bible are the product of a direct, supernatural influence of the Spirit on the men who were his organs or instruments. It is completely inerrant."  Everything documented in the closed canon of Scripture is God-breathed. And because the Scripture is God-breathed it is without error and will continue to be preserved. Not only that, but the God-breathed Scripture necessitates our humble submission to its every word.
Sam Waldron in A Modern Exposition of the 1689 Baptist Confession of Faith, 41.