Proclaimed as the biggest best seller of all time, it has inspired artists throughout the ages. But no one knows exactly how, or even when, the Bible was first written. Although scholars and archaeologists have begun to piece together its history, there remain many gaps in our knowledge and experts continue to argue fiercely about key aspects of the story.

What is the Bible, and how did it come to be written? Today it is presented as a single volume. The sections within it follow a prescribed order - Genesis, Exodus, Leviticus and so on. But it didn’t start life as a book. It was a collection of scrolls written on papyrus and stored in earthenware jars. Those that now form the Christian Old Testament dealt with the history and laws, the prophets and teachings of the Jews who lived before the time of Christ. They were not arranged in any particular order because they were not intended to be read sequentially. The Old Testament was not a single narrative, it was a library. During the first century AD this fluid arrangement was formalised into a recognised list of books that form the basis of the Hebrew Bible and the Old Testament.

At about the same time, the early Christians recorded and collated four versions of the life of Jesus, to which was added an account of the events immediately following his death and some of the letters written by the early apostles. This, together with the Book of Revelations, forms the New Testament. So, in effect, we have a collection of texts written for different purposes. Some are histories and, by convention, they are arranged in chronological order. But they are interspersed with other material from entirely different genres. For example, in the first section, the Pentateuch (the name for the first five books of the Old Testament, which are regarded as a unity), we find Genesis and Exodus, which tell the story of the Israelites from the creation of the universe to the arrival in the Promised Land.

Another anomaly is that some stories appear more than once. There are two versions of the Creation, for instance. Furthermore, there are inconsistencies in the story of the Flood, as if two different tellings have been combined into one narrative. This leads some scholars to argue that the Pentateuch draws on the oral histories of different tribes and that these were later written down and collated into one single version. Three of these books - Leviticus, Numbers and Deuteronomy - are not narratives at all. They consist of detailed codes of law covering every aspect of everyday life.

The histories

Between them, the histories tell the story of the children of Israel and the judges and kings through the time of exile in Babylon and their return to the Promised Land.

The ancient civilisations of the Middle East, the Egyptians, the Assyrians and the Persians, weave their way in and out, but they are extras in the great story of God’s covenant with his chosen people. Though we call them histories, these books were never intended as objective accounts of past events. They were set within a clear religious framework and their purpose was to describe what a proper kingdom under God should be like and to warn of the consequences of deviating from that ideal.

The prophets

The prophets arose at a time of crisis and their teachings were a response to the events of their day. Although it was believed that their special gifts enabled them to see more clearly than their contemporaries, they were reformers and political advisers rather than foretellers of the future. Each book of prophecy (Isaiah, Jeremiah and Ezekiel) contains the poems and thoughts of the man after whom it was named. It’s not always clear whether a book was written by the prophet or his disciples, but the works were certainly edited and modified over a long period of time to meet changing circumstances.

Words of wisdom

Some of the books of the Bible consist of songs and poetry, sayings and reflections on life. This is called the Wisdom literature. The book of Psalms is a collection of songs of praise, thanksgiving and entreaty, which were, by tradition, ascribed to King David. Some were believed to go back to the time of Moses and it seems likely that they were composed over many generations.

David’s son Solomon, famous for his wisdom, is credited with producing the book of Proverbs. He may have had a hand in collecting them, but it seems likely that the sayings are the work of many authors and that they were handed down by word of mouth through the generations before they were recorded in their present form. Many of the phrases and sayings have entered into our language. For example, “Spare the rod and spoil the child” and “Pride goes before a fall” are both derived from Proverbs. Some are very beautiful: “a word fitly spoken is like apples of gold in pictures of silver”, while others have a sharply contemporary ring: “Wealth makes many friends”.

The Wisdom books were probably used for teaching. It seems likely that the story of Jonah, who was swallowed by a whale, is a parable that tries to explain one aspect of God’s relationship with his chosen people. The story of Job, who remained faithful through awful tribulations, is another example. Some of the books, such as Esther, may have been drawn from the literature of the royal courts of the period.

The New Testament

As with the Old Testament, we don’t know who wrote most of the New Testament. We think that it began to take shape around two or three generations after the events described in the gospels by the apostles St Matthew, St Mark, St Luke and St John.

To begin with, the early Christian followers saw no need to record what had happened. They believed that the return of Jesus and the coming of the kingdom of God were imminent so there was little point in preserving the stories, which everyone knew anyway. But as time passed it became clear that memories were fading and that there was a need to make a record for future generations.

The first three gospels, Matthew, Mark and Luke, have a lot in common. They generally agree on the sequence of events they describe and this has led some scholars to claim that they are all based on a single collection of Jesus’s sayings and works. Mark is believed to be the earliest gospel, with Matthew coming next. According to the apostle Paul, Luke was a doctor. His gospel, together with the Book of Acts, is addressed to a Roman named Theophilus, and it is believed that both books have the same author. John is quite different from the other three gospels in tone and in some of the details it describes. His book is probably the last to have been written and it seems likely that it was produced about a century after the birth of Christ. There is a tradition that John was one of the disciples. If so, the gospel, although based on his memories, was produced many years after his death. Most of the rest of the New Testament is made up of letters written by the apostles to the infant churches of the Roman world.

The Bible and other faiths

Three world religions draw on Old Testament traditions. Jews call the first five books of the Bible (the Pentateuch in Christian tradition) the Torah, and they are the foundation of the Jewish religion. Most of the Old Testament books are included in the Hebrew Bible. However, some versions of the Old Testament contain additional Jewish scriptures known as the Apocrypha, or hidden books.

The Koran, which was written some 700 years later, refers to some of the events and personalities described in the Old Testament. It tells how Adam, the first man, is expelled from Paradise for eating from the forbidden tree and recounts the stories of Noah and the Exodus from Egypt. But although the outlines of the stories are similar, their treatment and the morals drawn from them are different.