Answer
The books of the Bible were written at different times by various authors over a span of about 1,500 years. However, this does not mean that it took 1,500 years to write the Bible; it simply took that long for the complete canon of Scripture to be composed as God gradually revealed His Word. Most scholars believe that the oldest book of the Bible is either Genesis or Job, both attributed to Moses and finalized around 1400 BC, approximately 3,400 years ago. The most recent book, Revelation, was penned around AD 90.
The books of the Bible were not composed continuously. For instance, there was a 400-year gap between the completion of the last book of the Old Testament, Malachi, and the commencement of the New Testament with the gospel of Matthew. This period of “400 years of silence” occurred because the Spirit of God did not inspire any Scripture during that time. Although Matthew’s gospel appears first in the New Testament, it is believed that the initial New Testament book written was actually the epistle of James, composed around AD 44–49. The entire New Testament was written in about 50 years, from AD 44 to 90 or 95.
It is impossible to determine how long each author took to write their specific book. Moses wrote the first five books of the Old Testament over about 40 years (1445–1405 BC). However, this does not necessarily mean he was continuously writing for 40 years. Paul’s letters to the New Testament churches, particularly the shorter ones like Philemon, might have been written in one sitting. The same could be said for 2 John and 3 John, which are brief letters addressed to specific individuals.
What we do know is that each of the Bible’s authors wrote only as much and as long as they were guided to do so. Each author wrote under the guidance of the Holy Spirit who “breathed out” Scripture to them. Peter elaborates on this process: “Prophecy never had its origin in the human w”Ill, but prophets, though human, spoke from God as they were carried along by the Holy Spirit” (2 Peter 1:21; cf: 2 Timothy 3:16).