HOW DO WE KNOW THE BIBLE IS THE WORD OF GOD ?
If the Bible is the inerrant and infallible word of God, as it claims
(2 Timothy 3:16; 2 Peter 1:21), we would expect there to be some evidence supporting these claims. After all, just because something claims to be the word of God does not make it true. We will examine the testimony of historical evidence to ask, Does the evidence support or deny the internal claims of the Bible?
Three tests can be applied to the Bible to see if it exhibits characteristics of a divine book that is without error. First, external evidence should confirm the truthfulness of the Bible in areas we can investigate. Second, internal evidence should show that, in one way or another, the Bible is unique. While these tests can establish the reliability of the Bible and lend support to the Bible's claims, they cannot prove its inspiration. However, the third test, a brief overview of Bible prophecy, will actually serve to verify the claim of divine inspiration.
The Testimony of History
External evidence from both archaeology and non-Christian writers confirms that the Bible--both Old and New Testaments -- is a trustworthy historical document. Archaeologist Joseph Free has
said that "Archaeology has confirmed countless passages which had been rejected by critics as unhistorical or contrary to known facts."  Renowned Jewish archaeologist Nelson Gluek confidently said that "It ... may be stated categorically that no archaeological discovery has ever controverted a biblical reference. Scores of archeological findings have been made which confirm in clear outline or exact detail historical statements in the Bible."  Christian apologist Josh McDowell tells us that "After personally trying to shatter the historicity and validity of the Scriptures, I have come to the conclusion that they are historically trustworthy." 
Some scholars once said that Moses couldn't have written the first five books of the Bible (as the Bible says) because writing was largely unknown in his day. Then, archaeology proved otherwise by the discovery of many other written codes of the period: the code of Hammurabi (ca. 1700 B.C.), the Lipit-Ishtar code (ca. 1860), and the Laws of Eshnunna (ca. 1950 B.C.).
Critics used to say that the biblical description of the Hittite Empire was wrong because the Hittite Empire (they though) didn't even exist! Then archaeologists discovered the Hittite capital in 1906 and discovered that the Hittite's were actually a very vast and prominent civilization. Archaeological and linguistic evidence is increasingly pointing to a sixth-century B.C. date for the book of Daniel, in spite of the many critics who attempt to late-date Daniel and make it a prophecy after the detailed events it predicts.
For the New Testament, Dr. G.R. Habermas points out that within 110 years of Christ's crucifixion, approximately eighteen
non-Christian sources mention more than "one hundred facts, beliefs, and teachings from the life of Christ and early Christendom. These items, I might add, mention almost every major detail of Jesus' life, including miracles, the Resurrection, and His claims to deity."  Sir William Ramsey, one of the greatest archeologists to ever live, demonstrated that Luke made no mistakes in references to 32 countries, 54 cities, and 9 islands.
Liberal scholars used to argue that a town named Nazareth didn't exist at the time of Jesus, until archaeology of the last few decades confirmed its existence. The Gospel's portrayals of the temple, Pilate's court, Jesus' crown of thorns, and the mode of His execution have all also been confirmed. The list could go on and on.
The historical evidence clearly shows that the Bible is a reliable historical document. Since the Bible can be trusted in areas that we can check (its history), then this gives us a reason to trust it in areas that we cannot check (its claims for inspiration).
The Uniqueness of the Bible
The internal evidence test reveals the Bible's amazing consistency. The Bible was written by over 40 authors, in 3 languages, on 3 continents, over a span of 1,500 years, and covers hundreds of controversial subjects. Yet, the authors all spoke with agreement; there are no contradictions.  From Genesis to Revelation, there is one unfolding story -- God's redemption of mankind.
The external and internal evidence tests do not prove the Bible's inspiration, but do reveal that the objective evidence is consistent with and supports the Bible's claims to be a divine book (because any book from God that claims to be inerrant should be reliable and consistent with itself). Bible prophecy, however, can only be explained by divine revelation and inspiration.
There are hundreds of specific prophecies in the Bible which have been literally fulfilled, in many cases centuries after the completion of the Bible. Any attempt to late-date these prophecies is impossible -- there is a copy of every Old Testament book but one from before 150 BC, and hundreds of these prophecies were not fulfilled until centuries later. For a detailed discussion of this area, see Evidence that Demands a Verdict by Josh McDowell.
Some prophecies fulfilled by Jesus are Micah 5:2, which revealed where He would be born; Isaiah 53 detailed His suffering, work at the cross, and resurrection; Psalm 22 is striking prophecy of the crucifixion.
Norman Geisler explains Ezekiel's prediction that the city of Tyre "would be destroyed and its ruins cast into the sea (26:2). This provoked scoffing because, when Nebuchadnezzar destroyed Tyre, he left the ruins right where they fell -- on the land. But 200 years later, Alexander the Great attacked Tyre and the inhabitants withdrew to an island just off the coast for safety. In order to reach them, Alexander threw all of the debris, stones, timbers, dust, and everything else, into the sea to build a causeway that would reach the island."  If events so far in the future can be accurately predicted, certainly the events of the past have been accurately recorded!
Has the text of the Bible Been Altered Over the Centuries?
One last test investigates whether or not the Bible has been corrupted down through the ages in its transmission. If it has been significantly changed, then it would not be relevant to us since inspiration does not extend to any manuscript copy. How can we know whether or not the Bible we have today is the same as what was written?
This question is answered by the bibliographical test. This test
looks at the number of existing manuscript copies there are, their agreement with each other concerning the text that they are copies of, and the time interval between these copies and the date of the original writing. All scholars agree that this test has conclusively established that the biblical text which we have now is nearly identical to what was originally recorded (for both Old and New Testaments).
Sir Frederick Kenyon, who was second to none in issuing statements about manuscripts, said this about the New Testament: "The interval between the dates of original composition and the earliest existing evidence [i.e. the earliest copies we have] become so small to be in fact negligible, and the last foundation for any doubt that the Scriptures have come down to us substantially has having been written has now been removed. Both the authenticity and general integrity of the New Testament may be regarded as finally established."  He further said that "No fundamental doctrine of the Christian faith rests on a disputed reading."
The discovery of the Dead Sea Scrolls, which date from 200 B.C. to A.D. 68, included a copy of every Old Testament book except for one. Comparison with the texts of a thousand years later shows little or no variation and change between them.
The historical evidence shows that the Bible can be trusted. The commonly held idea that the Bible is unreliable or "just a myth" is unfounded. The internal evidence reveals the uniqueness of the Bible, a uniqueness which would be difficult to explain if it was just a human book. These two tests give credibility to the Bible's internal claims to be the word of God. The testimony of predictive prophecy, however, takes us a step further and confirms the Bible's claims to be inspired by God. Finally, the Bible has not been changed through the ages. The evidence shows that there is good reason to believe in the Bible.
Joseph Free. Archaeology and Bible History (Wheaton, Illinois: Scripture Press, 1969), p. 1.
Nelson Glueck. Rivers in the Desert (New York: Farar, Straus and Cudahy, 1959), p. 136.
Josh McDowell, More Than a Carpenter (Wheaton, Illinois: Tyndale House Publishers, 1977), p. 57.
Gary Habermas and Antony Flew. Did Jesus Rise From the Dead? (San Francisco: Harper and Row, 1987), p. 43.
I have personally looked into the issue of alleged contradictions, and after thorough investigation, have never found one to hold. Norman Geisler, who has studied the Bible exhaustively for over forty years and been confronted with numerous difficulties, is of the same conclusion. A valuable resource for further investigation on this mater is Geisler's When Critics Ask.
Norman Geisler and Ronald Brooks. When Skeptics Ask (Wheaton, Illinois: Victor Books, 1990), p. 198.
Sir Frederic Kenyon. The Bible and Archaeology (New York: Harper and Row, 1940), pp. 288-289.
For further resources on this matter, consult I'm Glad You Asked by Ken Boa and Larry Moody or Evidence that Demands a Verdict by Josh McDowell.
The above article is reproduced from www.gospel outreach.net