The Bible was written over a long period by about forty different writers. They used three different languages and wrote on three different continents, and yet each part has the same thing to say about life's most controversial issues.
The Bible, as said before, is divided into two parts or 'Testaments'. The first part, the Old Testament, tells of God's dealings with the people of Israel. The second part, the New Testament, tells of the life of Jesus and His early followers, and includes letters written to help the early believers to hold fast to the teachings of Jesus.
The Bible is the inspired record of the revelation of God and not merely the chance compilation of a collection of human authors. It is God who directed his people. He revealed his word in normal human literary forms such as historical narrative, poetry, proverbs, preaching and didactic teaching.
"All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work." To a Muslim this concept is not new, for it is a fundamental part of the teaching of the Qur'an .
The Old Testament
We find the expression, "Thus says the Lord" more than 3,800 times in the Old Testament. This makes clear the writers' belief that they spoke or wrote on God's behalf. We see that people of God, like Moses and David, were inspired by God. Although the Old Testament was written by many writers over many years, the dealings of God with men remain the same and so there is one overall picture which emerges.
Some important examples
The Bible records that God spoke to Moses: "Now go; I will help you speak and will teach you what to say."  This clearly teaches that Moses was inspired by God. God also spoke through David when he said, "The Spirit of the Lord spoke through me; His word was on my tongue." We find similar evidence in the books of the prophets. For example, Jeremiah records that the Lord told him, "I have put My words in your mouth." 
There were many ways in which God made His will known in the Old Testament. He not only revealed His will through those who spoke His words, but also through the lives of those He touched; for example, the stories of Ruth and Job. All these, in very different ways, show the character of God and the way in which His love for His world reaches across time and space to care for individual people.
The verdict of Jesus
We also see that Jesus believed the Old Testament to be the Word of God, when He said, "Everything must be fulfilled that is written about Me in the Law of Moses, the Prophets and the Psalms." These three divisions include all the Old Testament.
Jesus also endorsed the New Testament before it was written. Before His crucifixion, He told His disciples that when the Holy Spirit came, He would remind them of the things He had said. He promised that the Holy Spirit would guide them into all truth.  That is why the apostles testified that they spoke "not in words taught us by human wisdom but in words taught by the Spirit."
God used many methods to reveal his word to people. He give his word to some by direct speech and to others through dreams and visions. His Holy Spirit guided them as they wrote or said using their full, normal faculties of intelligence and personal style. God gave them the freedom to write and say through their own individual background, personality, vocabulary and style. If the writers of the Bible had been mere pens, instead of men, in the hands of God, its style and vocabulary would have been uniform. But such is not the case since we see their individuality coming through. Nevertheless behind them all is God and His revelation of Himself. This gives the Bible unity.
Unity in the message
From beginning to end, there is one story of God's plan of salvation for mankind. There is one message throughout the Bible because there is one God and there is one mankind. God does not change, nor do the problems which face mankind. The greatest problem faced by man is: how to know God. God has made it plain that He is holy, all holy, and that man does not live a holy life and so cannot know a holy God. The Bible addresses this universal problem. In its message the Bible says that God himself has provided the answer to it. We will consider this answer more fully in later chapters.
- 2 Peter 1:20-2
- 2 Timothy 3:16-17
- Qur'an 2:136; 5:47; 10:95; 29:46
- Exodus 4:12
- 2 Samuel 23:2
- Jeremiah 1:9
- Luke 24:44
- John 14:26; 16:13; 1 John 2:20,27
- 1 Corinthians 2:13
- John 14:6
- 1 Timothy 2:4; 2 Peter 3:9