39 books in some Old Testament
27 books in that New Testament.
Where did they come from? Why were they written? Why are these the only books in the Bible? And how do we know they are the Word of God?
The Bible isn't just like any other book. In fact, it isn't one book - though all its parts speak in perfect unity. It is the canonized (completed) compilation of God's revelation to mankind. But how can we be sure?
1) The Bible isn't flat. It has high points. Peaks. Parts that everything else points back to - or forward to. For example: The first five books of the Bible, the Torah or Pentateuch, were written by Moses. Before Moses there were no Scriptures. God's Word was only spoken, but God used Moses to record His Word. And this is significant, because all the people of God (the Israelites) KNEW that God spoke to Moses. They were miraculously freed from the slavery of Egypt because God used Moses. They were preserved in the wilderness for forty years because God used Moses. They received God's covenant promise and His Law because God used Moses.
Moses is reliable, and that is seen throughout the rest of the Old Testament. All the prophets after him do two things. They point back to what God said through him - to the Torah or Pentateuch. And they point forward to the Christ. This was the test to see if they were authentic.
So not just anyone can come claiming they have a Word from God. Everything they say is compared against Moses. Everything they speak is tested - and as God established through Moses - the punishment for speaking falsely in God's Name is death. False prophets are put to death.
Yet there were many, as there are today. So another criterion was established for determining authenticity. Not only did the prophet have to be in full agreement with Moses. Not only did the prophet have to be speak of the coming Messiah. All they said had to come true. Anything he said that would happen - had to happen - or his writings were destroyed.
This is how the writings of the Scriptures were known to be reliable. God spoke in advance, and then when His true prophets words came true - those writings were retained. And about 300 years before Jesus was born the Old Testament was completed. Closed. Set as a whole unit. But the best part is they can still be tested. The Word is still accountable to itself. Any part of the Scriptures can be tested against the Torah - tested against the writings of Moses whom God used to establish a people that everyone knows exists.
And this is where it all leads: "In many and various ways God spoke to His people of old by the prophets, but now in these last days He has spoken to us by His Son." (Heb. 1:1)
God's revealed will - what He wants us to know about who He is, what He has done for us, and what He thinks is good - was all about Jesus. Jesus is the revelation. He is the Word. First He spoke using Moses, then other prophets - but it was all leading to His own coming in our flesh - His own Words from His own Lips. All the words He spoke through the prophets were spoken so we would know it was Him when He came. "All the Scriptures bear witness about me" John 5:39. "Everything written about me in the Law of Moses and the Prophets and Psalms must be fulfilled" Luke 24:44. Because God is a God who speaks - who communicates - who declares you righteous on account of His own righteousness shed for you on the cross. This is why the Bible was written - that you may believe that Jesus is the Christ, the Son of God, and by believing you may have life in His Name.
The Bible is the Word of God. Your certain, true, reliable testimony from God concerning His Son and the salvation that is found only in Him. You want to know where the Bible comes from - it comes from God.