So the Torah, God's instructions for living, was infused by God with a mathematical Checksum system to insure its integrity. But what about the rest of the Old Testament.
Well, first let's consider that the Torah was dictated to Moses from God Himself aurally. That is, that Moses could physically hear the voice of God. Just like the million or so Israelites who endured the thundering voice of God as He announced the Ten Commandments to them. They decided that this was less than a pleasant experience, and that if Moses was immune to the discomfort, then it was ok with them if Moses just told them what God said, and so the Torah was written. The million or more people who were at Mt. Sinai were fully convinced that Moses was faithful and accurate in his transmitting the words of God, Himself, to the people, and so should we, but what about the other books?
Well, God, in His mathematically secure Torah, conveyed instructions for how to test and receive the message of those who purported to speak for Him.
This instruction is that God means what He says, and says what He means. He may send a prophet to give a topically relevant message about a situation or event, but He's not changing his mind about what He already stated.
"You shall not add to the word which I am commanding you, nor take away from it, that you may keep the commandments of YHVH your God which I command you." Deuteronomy 4:2 New American Standard Bible (NASB) Name corrected."Whatever I command you, you shall be careful to do; you shall not add to, nor take away from it." Deuteronomy 12:32 New American Standard Bible (NASB)So, a Prophet may restate something that God has already said.
"Consult God's instruction and the testimony of warning. If anyone does not speak according to this word, they have no light of dawn." Isaiah 8:20 New International Version (NIV)
But if they try to change something God has already said, then that would "prove" that whatever he was saying wasn't from God, especially if it directed you away from God himself.
"If a prophet stands up in your midst or a dreamer of dreams
and he gives to you a sign or wonder,
2 and the sign or the wonder comes about that he spoke to you,
saying, 'Let us go after other gods (those whom you have not known), and let us serve them'
3 you must not listen to the words of that prophet or to that dreamer,
for Yahweh your God is testing you
to know whether you love Yahweh your God with all of your heart and with all of your inner self.
4 You shall go after Yahweh your God, and him you shall revere,
and his commandment you shall keep,
and to his voice you shall listen,
and him you shall serve, and to him you shall hold fast.
5 But that prophet or the dreamer of that dream shall be executed,
for he spoke falsely about Yahweh your God
the one bringing you out from the land of Egypt and the one redeeming you from the house of slavery,
in order to seduce you from the way that Yahweh your God commanded you to go in it; so in this way you shall purge the evil from your midst. Deuteronomy 13:1-5 Lexham English Bible.
So, a Prophet may restate something God has already said without any problem. But if he states something new, it must not contradict anything that God has already stated. This is an important, foundational pricipal that you should always keep in mind, and we will be referring back to it later.
The Old Testament is grouped into three sections by the people who wrote it. These three sections are:
1) The Torah. The first five books of the Old Testament are called the Torah or sometimes the Pentatuch. God dictated these five "books" to Moses verbally. Moses wrote them down, and these five books are referred to as the "written Law". Moses wrote down these five books on lambs skin, rolled them up into a scroll and commanded it to be placed "beside" the Ark of the Covenant. You know "the Lost Ark".
In 2nd Kings chapter 22 we read about how King Josiah had his work crews do some restoration to the Temple. There they "found" a scroll of the Law. This passage suggests that the King and the priests had forgotten about God's Law and discarded any "copies" of it. Most scholars believe that by this time the temple of God had become like a garage, stuffed full of forgotton "stuff". When King Josiah has his work crews "clean out" this mess, his work crews found "a copy" (scroll) of the law. But I believe that there is only one mention of any scroll being kept in the inner temple, the Holy of Holies. I believe that they found the original scroll of the Law. This scroll of Moses had survived, (by the providence of God). I believe that all of the copies we have of the Torah originate with this refound scroll. After they made copies of it, I believe that they put it back beside the Ark of the Covenant where it waits to be discovered once again, a witness to the faithfulness of God and his word.
2) The Prophets. The word of the LORD came unto the prophet so and so, is how most of these books start. Then you will read "thus saith the LORD God of Hosts". These are the written record of direct messages from the throne room of God as given to God's messengers, his prophets. The Torah guidelines defined who could and who could not be included as a prophet in the prophetic section of the Old Testament.
We know that the religious leaders during the Old Testament times did a bloody and brutal job of including and excluding which "prophets" should be, and should not be, included in the Prophetic section of the Old Testament. Jesus was a witness of God's acceptance of this list of "Old Testament" prophets.
In the King James Version of the Bible Jesus said:
"Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfill."Matthew 5:17 KJVPersonally, I think that the GOD'S WORD translation conveys the meaning more accurately:"Don't ever think that I came to set aside Moses' Teachings or the Prophets. I didn't come to set them aside but to make them come true." Matthew 5:17 GOD'S WORD Translation
3) The Other Writing. These are just what the title says they are. The writings of men about God, and their relatioinship with God. These writings have been recognized as not being the words of God, but the God inspired writings of men about God.
These other writings include The Psalms, Proverbs, Lamentations, The Song of Solomen and other non prophetic books.
So, the Old Testament is founded by the very words of God the Father.
What about the New Testament?