The books of the Bible were not being written continuously. The newest book, Revelation, was written around AD 90.
The oldest book of the Bible, according to most scholars, is either Genesis or Job, both thought to have been written by Moses and completed around 1400 BC, about 3,400 years ago. But that is not to say that it took 1,500 years to write the Bible, only that it took that long for the complete canon of Scripture to be penned as God progressively revealed His Word.
The books of the Bible were written at different times by different authors over a period of approximately 1,500 years.
