There's no doubt that this is an important question. If the Bible is the Word of God, it changes everything – the way we view life, the way we live life, and the choices we make. If the Bible is the Word of God, then the Bible is true, and failure to follow, obey and trust it will have eternal consequences. To ignore God's Word is to ignore God Himself.
Is the Bible really the Word of God?
God's love is proved by the existence of the Bible. God did not have to communicate to mankind, but He chose to so that we could know Him, enjoy fellowship with Him, and understand ourselves and the world. If He had not taken the first step to reveal Himself to us through His Word, we simply would not know Him, and we would be left to deduce what we could about the world from what we could sense. But God has graciously shown us the Truth, and it is contained in the Bible. Since God is our Creator (Isaiah 40:28), He is our authority (Isaiah 43:15), and His Word is the final authority for humankind, and the only entirely trustworthy moral litmus test (1 John 2:5). It explains life and death and gives us a clear understanding of right and wrong.
So, how do we know for sure that the Bible we have is the actual Word of God? Could the Bible be just another holy book? What is the evidence that the Bible we buy in the bookstore today is truly the Word of God? First, the Bible itself claims to be the Word of God, in 2 Timothy 3:15-17, which says "and how from childhood you have been acquainted with the sacred writings, which are able to make you wise for salvation through faith in Christ Jesus. All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work."
This is an example of an "internal" evidence that the Bible is the Word of God. Internal evidences are those things stated within the Bible that claim its divine origin. A few other internal evidences are the unity of the Bible, the fulfilled prophecies in the Bible, and the unique, powerful authority of the Bible.
The unity of the Bible means that, even though it was written by more than 40 different authors over three continents, in three different languages, and is comprised of 66 individual documents, it is cohesive down to the last detail. Every supposed contradiction in the Bible can be answered in a satisfactory way. There are no mistakes, and it all works together perfectly. That's a miracle!
The fulfilled prophecies in the Bible also indicate that it is God's Word. Hundreds of prophecies about future kingdoms and nations, and most importantly, the Messiah, were spoken forth and then fulfilled, sometimes hundreds of years later. This is all recorded within the Bible itself. Unlike many modern prophecies, the prophecies in Scripture are very detailed and are fulfilled exactly. There is no way this happened by chance. The only answer is that the Bible is of divine origin.
The Bible's unique authority and power is another internal evidence for its divine origin. This power is revealed by the millions of lives that have been changed by it over the course of human history. Martyrs have given their lives up to preserve its truth. Sinners throughout the ages have been convicted and changed by it, broken hearts have been healed by God's comforting voice coming through its pages, and salvation has been graciously made available through its record of the life and sacrifice of Jesus Christ. No other book in human history has the power to change lives like the Bible, the Word of the God who created life.
In addition to the internal evidences, there are also external evidences that the Bible is God's Word. The Bible's historicity, the integrity of its human authors, and its indestructibility.
The "historicity of the Bible" means it is true and accurate to the historical events recorded by non-religious sources. Archaeological events and historical writings prove the Bible to be true. It is the best-documented book from the ancient world. The accurate historical records found in the Bible give us proof of its truthfulness about spiritual subjects.
The integrity of its human authors is another external evidence of its truthfulness. When the lives of the authors of Scripture are studied, they are found to be honest men. Their willingness to die for what they believed shows that they were sure of their testimonies. Those who wrote the New Testament (and hundreds of others) had seen Jesus Christ after He rose from the dead. If they had been lying about seeing Him, there is no doubt that at least one of them would have been unwilling to die for what he believed to be false. But all the apostles, without exception, remained true to their testimonies until the end of their lives (1 Corinthians 15:6).
The indestructibility of the Bible is another strong evidence that it is indeed God's Word. Because of its offensive message, which in contrast to every other religion humbles man's ability to save himself and provides the need for God's grace instead (Ephesians 2:8-9), the Bible has endured more attacks and attempts to eliminate it than any other book in history. From the early Romans, to the communist dictators, to the atheists and agnostics of modernism and postmodernism, the Bible has survived and is still published more than any other book worldwide.
Over the ages, scoffers have called the Bible a myth, but archeological records have proved its historicity. Others have denounced its teachings as outdated and useless, but its positive impact on the moral and legal systems of cultures around the world is undeniable. Scientists, psychologists and politicians continue to attack the Bible, but its truth has never been disproven and its light has never been snuffed out. It continues to change lives and cultures just as it did 2,000 years ago. God supernaturally protects the Bible, proving that it is indeed His Word, just as it claims to be. Jesus said, "Heaven and earth will pass away, but my words will not pass away" (Mark 13:31). When all the evidence is before us, there is no doubt that the Bible is truly the Word of God.
How is the Bible inspired? What does it mean for the Bible to be inspired?
What is the meaning of God-breathed in reference to the Bible?
Are there errors in the Bible?
What is the canon of the Bible and how did we get it?
Why should we study the Bible?
Truth about the Bible