The Old Testament is rich with occasions when God speaks with humans. According to the book of Genesis, God spoke to Adam and Eve, he spoke to Noah, he spoke to Abraham. Abraham had a special relationship with God because he is called the first prophet and God's friend. (Genesis 1:28; 6:13; 18:16-21; 20:6-7)
Later on we find that God speaks to Moses, Samuel, David, Solomon and to a host of people who are called prophets. The word prophet means to be God's mouthpiece. The message the prophets had to speak from God, many times was not received well by the people. The Israelites persecuted and killed Isaiah; they asked Amos to go back to his place and stop prophesying, and Jeremiah tells God that he no longer wants to speak in His name because of the peoples' reaction. (Isaiah 6:1-13; Amos 7:10-16; Jeremiah 20:7-18)
We find out that God had spoken extensively to a person who lived outside of the Jewish territories - namely Job. In fact, for many people, the beginning chapter of the book and the last five chapters present some of the most fascinating detailed descriptions about the work of God in the universe and with the angelic orders. (Job 1, 38-42)
For many centuries, what God spoke was a part of the Jewish oral tradition. The Israelites could discuss the fact that God had appeared to their forefathers Abraham, Isaac and Jacob. It is during the time of Moses that we have the presentation of the written text. God writes the Ten Commandments and the future kings are asked to write for themselves a book of the law so that they would learn how to lead God's people. It is in this time that terms such as seers, prophets, scribes, and chroniclers become a part of the Jewish vocabulary. Moreover, a whole tribe is selected - the tribe of Levi - to be priests and to teach the nation of Israel the laws and the precepts of the Lord. The Psalms often extol the blessings that the Psalmists experience as they memorize the law of the Lord and live their lives based upon it.
However, it is in this time of direct revelation from God, that a danger comes on. It is called the false prophet. He is the person who speaks as though he has received a message from God, but who indeed is speaking in his own name. The test for the false prophet is to see if what he has prophesied came to be fulfilled. If the prophecy was not fulfilled or if other prophets declared him to be a false prophet, the punishment was very harsh - he would be stoned to death.
By the time of Jesus Christ, we find out that he talks about the Scriptures being fulfilled. Already at the tender age of 12 Jesus Christ is familiar with the Scriptures and discusses them with the scribes and the Pharisees. Paul talks about Timothy having known the Scriptures from infancy and tells about himself studying with the well-known rabbi Gamaliel. (Luke 2:41-52; 2 Timothy 3:15)
The inscripturation process or the activity of how individual books became a part of the Holy Scriptures (one book) is an interesting one. While the books of the law, the chronicles of the kings, the wisdom of the psalms and the proverbs were a part of the Jewish culture, it was the translation of this revelation into another language that has set the Jewish Scriptures apart. It is the translation of the Hebrew Bible into the Greek language, called the Septuagint, that sets the perimeters as to what is known and accepted as the revealed Word of Jehovah to his people, but now also to the world. In fact, Paul is familiar with both the Hebrew text and the Greek text and quotes interchangeably.
It is the recognition and acceptance that Jesus fulfills the OT prophecies that inspire the gospel writers to put into writing the words of Jesus that have circulated orally for many decades. As they see that the eyewitnesses are dying there is a necessity to put these collections together. Luke, who writes a gospel, makes the transition from the gospel that brings the teachings of Jesus, to the stories about the church, demonstrating that the church is continuing what Christ asked them to do.
The pivotal point is when the Gospel writers, and the apostles Peter, John and Paul sensed that what they were writing was equally authoritative as the Old Testament. They see themselves as being chosen to be eyewitness of the life of Jesus Christ and of being empowered by the Holy Spirit to write with authority the words of God. Both Peter and Paul are clear that what they are writing are not their own words - these are the words of God that need to be obeyed.
There are two specific realities to be watched at this time in Christian history. The first one is to see that those who can be called the second generation Christians do not feel that they have the authority to write Scripture. We have a whole book called The Didache in which the authors recognize that their exhortations do not compare with the gospels or the epistles. The second is a falsehood being spread widely in our times. This false teaching is that Emperor Constantine decided which books belonged to the New Testament. It is a neat answer, but it is a false answer.
Expanding on Peter's statement, "No prophecy came by the will of men", we can say historically that the canon or the choosing of the books which belonged to the Old and the New Testament, was not left to man's discretion. He, who inspired the prophets to speak the truth about God, watched over His Word while in it was in the oral tradition and watched over it as He chose the books which he wanted to become a part of the Holy Scriptures.
Bruce Metzger who has written extensively on the New Testament canon, asks the question: "What would happen to the New Testament if we find the letter that Paul has written to the Laodiceans?" We know that there is a Laodicean letter, because Paul tells the Colossians that when they have finished the letter that he sent to them, that they should send it to Laodiceans, and the Laodiceans will send to them the letter that they have received from Paul (Col. 4:16). Metzger's answer is that for all practical purposes the New Testament canon has been closed. There have been suggestions for other letters, both in the past and in the present, to be added to the New Testament, yet the church universal has always answered in the negative.