The Bible was written over a span of more than 1,500 years on three continents by more than 40 authors who were directed by God to record His Word. Thus, the Bible has both human and divine authorship. Second Peter 1:20-21 makes it clear “that no prophecy of Scripture comes from someone’s own interpretation. For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit.”
This co-authorship could be thought of in terms of a sailboat in the middle of open water being pushed and guided by the wind. The boat in this case represents the human author while the wind represents the Holy Spirit. The wind is the primary driving force, determining where the ship will go. 
With all of that in mind, we will now take a look at the human authors whom God used to bring His Word to His people. We will first look at the authors of the Old Testament according to the text and tradition. Then we will look at the authors of the New Testament.
Old Testament Authors
The first five books of the Bible (Genesis, Exodus, Leviticus, Numbers, and Deuteronomy) were written by Moses. Moses was a Hebrew who was born in Egypt at the time of a decree from Pharaoh to kill all of the baby boys. His mother put him into a basket in the river, and Pharaoh’s daughter found him. He was raised as her son and was later chosen by God to lead the Israelites out of the slavery. He led the Israelites in their wandering through the desert, and he represented the people before God when God revealed His Law to them.
First and Second Chronicles and Ezra were written by Ezra. Nehemiah was written by Nehemiah. Ezra and Nehemiah were key leaders who left Babylon to participate in the reconstruction of Jerusalem. Ezra was a priest and a scribe who led the exiled Jews back to Jerusalem and instructed them to obey and apply the Law. Nehemiah was an exile who believed in God’s promises and prayed for them to be fulfilled, and God granted him the privilege of leading the efforts to rebuild the walls around Jerusalem.
The Psalms and Proverbs were written by a variety of authors. David, Asaph, the sons of Korah, and Solomon all wrote multiple Psalms. Moses, Ethan, and Heman with Korah each wrote one Psalm. Solomon wrote 29 chapters of Proverbs while Agur and Lemuel each wrote one chapter. Ecclesiastes and Song of Solomon were both written by Solomon. David and Solomon were two kings of Israel. Despite their many failures and shortcomings, God considered David to be a man after His own heart, and He rewarded Solomon for his desire to obtain wisdom more than anything else.
Jeremiah wrote both Jeremiah and Lamentations. And the rest of the latter half of the Old Testament are the works of the prophets. Each of these books bears the name of its author. Among these are Isaiah, Ezekiel, Daniel, Hosea, Joel, and Amos. Obadiah, Jonah, Micah, Nahum, and Habakkuk are also in this list. And Habakkuk, Zephaniah, Haggai, Zechariah, and Malachi also bear the names of their authors. These writing prophets had different approaches, roles, and audiences, but they were all responsible for hearing a message from God and communicating it faithfully to God’s people.
The rest of the Old Testament books have unknown authorship. These books include Joshua, Judges, Ruth, 1 and 2 Samuel, 1 and 2 Kings, Esther, Job, and 50 of the Psalms.
New Testament Authors
The first three books of the New Testament are the Synoptic Gospel accounts and bear the name of their authors. Matthew was a Jewish tax collector who became a disciple of Jesus. His Gospel is primarily addressed to Jews. Mark was a companion of Peter, Paul, and Barnabas, and he wrote his Gospel for Gentile converts. Luke was a doctor and historian who was a fellow laborer with Paul and wrote his Gospel predominantly for gentiles. 
John was a fisherman who became one of the inner three most intimate disciples of Jesus. He wrote the fourth Gospel with various audiences in mind including Jews, Hellenists, and Samaritans. He also wrote the Epistles bearing his name (1 John, 2 John, and 3 John) and Revelation.
A vast majority of the letters of the New Testament were written by Paul. These include Romans, 1 Corinthians, 2 Corinthians, Galatians, Ephesians, and Philippians. Also among this list are Colossians, 1 Thessalonians, 2 Thessalonians, 1 Timothy, 2 Timothy, Titus, and Philemon. Paul was a devout Pharisee who prided himself in being zealous for God. He persecuted Christians and others who deviated from Judaism because he believed them to be blaspheming the name of God. It wasn’t until Jesus Himself appeared to Paul on the Road to Damascus that Paul realized that he was the one who had been sinning. He repented of his former way of life and became one of the greatest missionaries of the early church.
James the brother of Jesus wrote James. He did not accept Jesus’ ministry early on, but he became one of the first ones to witness the resurrection of Jesus. He finally accepted Jesus as Lord and Savior and became a prominent force in the early church in Jerusalem.
Peter wrote the letters bearing his name (1 Peter and 2 Peter). He was one of the earliest and closest disciples of Jesus and is known for his impulsive character in his early days. He was the first one to confess Jesus as the Messiah and Son of God, and he became a leader not only of the disciples but also of the early church.
Jude the brother of Jesus wrote Jude. Like James, he did not believe in the ministry of Jesus at first. But after witnessing the resurrection, he came to a place of true repentance and faith. He became a leader in the church and a servant of Jesus.
Hebrews is the only book in the New Testament with unknown authorship.
We see clearly as we read Scripture that God allowed these individual human authors to use their personalities, writing styles, and experiences in their writings. But ultimately, as 2 Timothy 3:16-17 teaches, “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.”