Let us first know, who wrote the Bible? According to both Jewish and Christian Dogma, the first five books of the Bible, the books of Genesis, Exodus, Leviticus, Numbers and Deuteronomy, were all written by Moses in about 1300 B.C. The problem arises as there is a lack of evidence that Moses ever existed and at the end of Deuteronomy describes the "author" dying and being buried. But the confusion or the doubt continues to exist with different theories. To date, there is no such confirmed information about this.
By the time of the 17 th century, the enlightenment began. Most of the religious scholars were more seriously questioning the idea of Moses' authorship and at the same time the idea that the Bible could have been the work of any single author. It is really hard to believe. Moreover, the five books have a lot of contradictory repetition and seem to tell different versions of the Israelites' story even within a single section of text.
Those Bible's contradictions, repetitions and general idiosyncrasies, today's most scholars agree that the stories and law it contains were mostly communicated orally, through prose and poetry, over centuries.
Though the scholars agree to comprise the Bible's first five books were believed to have been written by a group of priests whose work scholars designate as "P", the second block of the source material is known as D for Deuteronomist, the authors of the vast majority of the book of Deuteronomy.
For more than a century, scholars have generally agreed to the Gospels, like many of the books of the New Testament were not written by the people to whom that are attributed. So it is very clear that the stories that form the basis of Christianity were communicated orally from one generation to another and then written down.