Question: Why do you believe the bible?
Answer: Because it’s a reliable collection of historical documents written by eye witnesses during the lifetime of other eye witnesses that reported supernatural events in fulfillment of specific prophecies. Finally, they claim that these messages are divine rather than human in nature.
“Thus says the Lord”, and variations of the statement depending on what translation you’re studying with, appears all over the Old Testament. God’s prophets didn’t speak in their own names. They claimed to speak for God. God validated the authenticity of their claims with public signs.
This would not stop anyone from claiming to speak on behalf of God at any given time, but God has given us standards to look to. One of those is the aforementioned signs. The other is consistency with the truth. There are some verses that distinguish true prophets from those taking the Lord’s name in vain that we can look to (Deuteronomy 13:1-3 / 18:15-22).
This is the point that ties everything together. There is nothing of antiquity or otherwise that boasts the credentials of scripture. It was written over the span of roughly 1,500 years. The authors were the very rich on down to the very poor. These men spoke different languages. They lived in different places. Most of them never met one another. They even spoke into different topics that ultimately ties to one overarching narrative of redemption.
If you don’t know who Jesus is, there is no way to give a consistent answer to this (John 5:46). Red letter Christians aren’t gonna like this, but over and over Jesus claims not only to be the coming Messiah, but He’s also one with the God of Abraham (John 1:1). He’s the one that gave the words to the prophets of old to speak (John 8:48-59).
Unlike any of the other prophets, Jesus never uttered the words “Thus says the Lord” or any variation. He said “You have heard it said, but I say...”. He spoke on His own authority, which was unheard of and considered blasphemous. This is how we know for sure that all scripture is God breathed and profitable for teaching (2 Timothy 3:16-17). ALL of it comes from Jesus, not just words that were written in red ink starting in 1899.
If you still can’t get on board with Jesus, you’ve got to wrestle with this. Eternity is a long time to be wrong. All that time from start to finish. All those prophecies that just so happened to be fulfilled in one man that claimed to be God. All those public miracles acknowledged even by opposition to the church. That one empty tomb that no one can give account for outside of a resurrection. A church that spread like wildfire in the face agonizing persecution. What does all this say to you? Seek Jesus. None of this will make sense outside of Him.