The Bible doesn’t get its authority from man’s proofs or the church’s authority, but from God who authored it. There are all kinds of dangers here. When our favorite online preacher becomes too big in our influence, we might believe the Bible because of his assuring tone and words. If we are history buffs, we might believe the Bible because an archaeological find confirms Hezekiah really existed. The confession has an eye on the Roman Catholic assertion that the Church gives the Bible its authority, by its declaration that these texts are Scripture. No, it’s the other way around. The Bible gives the Church its authority to speak. When John the Baptist pointed out Jesus and said, “Behold the Lamb of God,” John was not giving Jesus his authority. John only recognized Jesus as already having authority, apart from him. So it is with the Church pointing to the Bible.
There is plenty of evidence right in the Bible of its truth and authority.
The unity of design by 40 different authors writing over a span of 1500 years.
The heavenliness of matter and majesty of style (see Genesis 1 and Isaiah 40 for examples).
What it teaches is self-evidently true (see Romans 1-2).
But only the Holy Spirit can fully persuade us of the Bible’s truth and authority (1 Corinthians 2:10, 14). The book of Acts gives us a glimpse of this a few times – that the Lord opens hearts to receive truth (Acts 16:14; 13:48).
This isn’t to endorse a “just me and my Bible” approach to the Christian life. This attitude says, why listen to anyone, if the Spirit is the ultimate source? No, we need the church’s witness and teaching about the Bible to grow in the Lord. Proofs and evidence further reinforce the authority of Scripture. But they are not the foundation of its authority.