The sixty-six books that make up the Bible were written over a span of approximately 1,500 years. This does not mean it took 1,500 solid years of writing to complete the Bible. Rather, it took this long for the entirety of the canon of Scripture to be completed, as God revealed His Word to people in His own timing. Most scholars believe that the earliest written book of the Bible is either Genesis or Job. Moses is thought to have written Genesis and possibly Job, both around 1400 BC, approximately 3,400 years ago. The book of Revelation is the newest book, and it was completed around AD 90.
How long did it take to write the Bible?
As mentioned, it did not take a full 1,500 years to write the Bible. There was a 400-year gap, for instance, between Malachi, the last book of the Old Testament, and the Gospel of Matthew that starts the New Testament. The Spirit of God did not inspire anyone to write any new Scripture during the "400 years of silence." Even though the book of Matthew comes first in order of the New Testament, the epistle of James is believed to have been penned earlier, around AD 44—49. It only took about fifty years for the entire New Testament to be written, about AD 44 to 90 or 95, so the Old Testament is what took the majority of the writing time for the Bible.
Since the Bible was written so long ago, there is no way for us to know how long each particular book took to write. Moses completed the Pentateuch, or the first five books of the Old Testament, between 1445—1405 BC, so in about forty years, but we don't know if he was writing continually for those forty years. Paul's epistles to the New Testament churches were letters, so many of the shorter ones may have even been written in one sitting. Both 2 John and 3 John are also brief letters, which could have been written in one sitting, to specific people. Jude is also quite short, as are some of the other epistles like 1 John, 1 and 2 Peter, and James.
Each author of the books of the Bible only wrote what the Holy Spirit inspired him to write: "All Scripture is breathed out by God" (2 Timothy 3:16). The apostle Peter further clarified this when talking of prophets speaking the Word of God: " 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" (2 Peter 1:21). The men who wrote the Bible were used of God to transcribe His words, thereby creating the Bible and sharing His message with the world to come.
Who wrote the Bible?
What is the canon of the Bible and how did we get it?
Why should I believe the Bible?
Is the Bible reliable?
The purpose of the Bible – What is it?
Truth about the Bible