A number of Christians have tried to answer this question. Unfortunately, not all of those answers have been as cogent as we might hope. Some answers make very little sense at all.

The Bible is an extraordinary work of literature, and it makes some astonishing claims. It records the details of the creation of the universe, the origin of life, the moral law of God, the history of man’s rebellion against God, and the historical details of God’s work of redemption for all who trust in His Son. Moreover, the Bible claims to be God’s revelation to mankind. If true, this has implications for all aspects of life: how we should live, why we exist, what happens when we die, and what our meaning and purpose is. But how do we know if the claims of the Bible are true?

Some Typical Answers

A number of Christians have tried to answer this question. Unfortunately, not all of those answers have been as cogent as we might hope. Some answers make very little sense at all. Others have some merit but fall short of proving the truth of the Bible with certainty. Let’s consider some of the arguments that have been put forth by Christians.

A Subjective Standard

Some Christians have argued for the truth of the Scriptures by pointing to the changes in their own lives that belief in the God who inspired the Bible has induced. Receiving Jesus as Lord is a life-changing experience that brings great joy. A believer is a “new creation” ( 2 Corinthians 5:17 ). However, this change does not in and of itself prove the Bible is true. People might experience positive feelings and changes by believing in a position that happens to be false.

At best, a changed life shows consistency with the Scriptures. We would expect a difference in attitudes and actions given that the Bible is true. Although giving a testimony is certainly acceptable, a changed life does not (by itself) demonstrate the truth of the Scriptures. Even an atheist might argue that his belief in atheism produces feelings of inner peace or satisfaction. This does not mean that his position is true.

By Faith

But the “by faith” response does not actually answer the objection that has been posed—namely, how we know that the Bible is true.

When asked how they know that the Bible is true, some Christians have answered, “We know the Bible is true by faith.” While that answer may sound pious, it is not very logical, nor is it a correct application of Scripture. Faith is the confident belief in something that you cannot perceive with your senses ( Hebrews 11:1 ). So when I believe without observation that the earth’s core is molten, I am acting on a type of faith. Likewise, when I believe in God whom I cannot directly see, I am acting on faith. Don’t misunderstand. We should indeed have faith in God and His Word. But the “by faith” response does not actually answer the objection that has been posed—namely, how we know that the Bible is true.

Since faith is a belief in something unseen, the above response is not a good argument. “We know by faith” is the equivalent of saying, “We know by believing.” But clearly, the act of believing in something doesn’t necessarily make it true. A person doesn’t really know something just by believing it. He simply believes it. So the response is essentially, “We believe because we believe.” While it is true that we believe, this answer is totally irrelevant to the question being asked. It is a non-answer. Such a response is not acceptable for a person who is a follower of Christ. The Bible teaches that we are to be ready to give an answer to anyone who asks a reason of the hope that is within us ( 1 Peter 3:15 ). Saying that we have faith is not the same as giving a reason for that faith.

Begging the Question

Some have cited 2 Timothy 3:16 as proof that the Bible is the inerrant Word of God. This text indicates that all Scripture is inspired by God (or “God-breathed”) and useful for teaching. That is, every writing in the Bible is a revelation from God that can be trusted as factually true. Clearly, if the Bible is given by revelation of the God of truth, then it can be trusted at every point as an accurate depiction. The problem with answering the question this way is that it presupposes that the verse itself is truthful—which is the very claim at issue.

In other words, how do we know that 2 Timothy 3:16 is true? “Well it’s in the Bible,” some might say. But how do we know the Bible is true? “ 2 Timothy 3:16 assures us that it is.” This is a vicious circular argument. It must first arbitrarily assume the very thing it is trying to prove. Circular reasoning of this type (while technically valid) is not useful in a debate because it does not prove anything beyond what it merely assumes. After all, this type of argument would be equally valid for any other book that claims to be inspired by God. How do we know that book X is inspired by God? “Because it says it is.” But how do we know that what it’s saying is true? “Well, God wouldn’t lie!”

On the other hand, some Christians might go too far the other way—thinking that what the Bible says about itself is utterly irrelevant to the question of its truthfulness or its inspiration from God. This, too, is a mistake. After all, how would we know that a book is inspired by God unless it claimed to be? Think about it: how do you know who wrote a particular book? The book itself usually states who the author is. Most people are willing to accept what a book says about itself unless they have good evidence to the contrary.

So it is quite relevant that the Bible itself claims to be inspired by God. It does claim that all of its assertions are true and useful for teaching. Such statements do prove at least that the writers of the Bible considered it to be not merely their own opinion, but in fact the inerrant Word of God. However, arguing that the Bible must be true solely on the basis that it says so is not a powerful argument. Yes, it is a relevant claim. But we need some additional information if we are to escape a vicious circle.

Textual Consistency and Uniqueness

Another argument for the truthfulness of the Bible concerns its uniqueness and internal consistency. The Bible is remarkably self-consistent, despite having been written by more than 40 different writers over a timespan of about 2,000 years. God’s moral law, man’s rebellion against God’s law, and God’s plan of salvation are the continuing themes throughout the pages of Scripture. This internal consistency is what we would expect if the Bible really is what it claims to be—God’s revelation.

Moreover, the Bible is uniquely authentic among ancient literary works in terms of the number of ancient manuscripts found and the smallness of the timescale between when the work was first written and the oldest extant manuscript (thereby minimizing any possibility of alteration from the original).1 This indicates that the Bible has been accurately transmitted throughout the ages, far more so than other ancient documents. Few people would doubt that Plato really wrote the works ascribed to him, and yet the Bible is far more authenticated. Such textual criticism shows at least that the Bible (1) is unique in ancient literature and (2) has been accurately transmitted throughout the ages. What we have today is a good representation of the original. No one could consistently argue that the Bible’s authenticity is in doubt unless he is willing to doubt all other works of antiquity (because they are far less substantiated).2

To be sure, this is what we would expect given the premise that the Bible is true. And yet, uniqueness and authenticity to the original do not necessarily prove that the source is true. They simply mean that the Bible is unique and has been accurately transmitted. This is consistent with the claim that the Bible is the Word of God, but it does not decisively prove the claim.

External Evidence

Some Christians have argued for the truth of Scripture on the basis of various lines of external evidence. For example, archaeological discoveries have confirmed many events of the Bible. The excavation of Jericho reveals that the walls of this city did indeed fall as described in the book of Joshua.3 Indeed, some passages of the Bible, which critics once claimed were merely myth, have now been confirmed archeologically. For example, the five cities of the plain described in Genesis 14:2 were once thought by secular scholars to be mythical, but ancient documents have been found that list these cities as part of ancient trade routes.4

Archaeology is an uncertain science; its findings are inevitably subject to the interpretation and bias of the observer and are sometimes overturned by newer evidence.

Archaeology certainly confirms Scripture. Yet it does not prove that the Bible is entirely true. After all, not every claim in Scripture has been confirmed archeologically. The Garden of Eden has never been found, nor has the Tower of Babel or Noah’s Ark (as of the writing of this article). So at best, archaeology demonstrates that some of the Bible is true.

Such consistency is to be expected. Yet, using archaeology in an attempt to prove the Bible seems inappropriate. After all, archaeology is an uncertain science; its findings are inevitably subject to the interpretation and bias of the observer and are sometimes overturned by newer evidence. Archaeology is useful, but fallible. Is it appropriate to use a fallible procedure to judge what claims to be the infallible Word of God? Using the less certain to judge the more certain seems logically flawed. Yes, archaeology can show consistency with Scripture but is not in a position to prove the Bible in any decisive way because archaeology itself is not decisive.

Predictive Prophecy and Divine Insight

A number of passages in the Bible predict future events in great detail—events that were future to the writers but are now in our past. For example, in Daniel 2 a prophecy predicted the next three world empires (up to and including the Roman Empire) and their falls. If the Bible were not inspired by God, how could its mere human writers possibly have known about events in the distant future?5

The Bible also touches on matters of science in ways that seem to go beyond what was known to humankind at the time. In Isaiah 40:22 we read about the spreading out (expansion) of the heavens (the universe). Yet secular scientists did not discover such expansion until the 1920s. The spherical nature of the earth and the fact that the earth hangs in space are suggested in Scriptures such as Job 26:10 and Job 26:7 respectively. The book of Job is thought to have been written around 2000 BC—long before the nature of our planet was generally known.

Such evidence is certainly consistent with the claim that the Bible is inspired by God. And some people find such evidence convincing. Yet, persons who tenaciously resist the idea that the Bible is the Word of God have offered their counterarguments to the above examples. They have suggested that the predictive prophetic passages were written after the fact, much later than the text itself would indicate. Examples of apparent scientific insight in the Bible are chalked up to coincidence.

Moreover, there is something inappropriate about using secular science to judge the claims of the Bible. As with archeological claims, what constitutes a scientific fact is often subject to the bias of the interpreter. Some people would claim that particles-to-people evolution is a scientific fact. Although creationists would disagree, we must concede that what some people think is good science does not always coincide with the Bible.

The Bible does show agreement with some of what is commonly accepted as scientific fact. But what is considered scientific fact today might not be tomorrow. We are once again in the embarrassing position of attempting to judge what claims to be infallible revelation from God by the questionable standards of men. Again, how can we judge what claims to be inerrant revelation by a standard that is itself uncertain and ever-changing? This would be like using something we merely suspect to be about three feet long to check whether a yardstick is accurate. Using the less-certain to judge the more-certain just doesn’t make sense. At best, such things merely show consistency.

The Standard of Standards

The above lines of evidence are certainly consistent with the premise that the Bible is true. Many people have no doubt found such evidence quite convincing. Yet, we must admit that none of the above lines of evidence quite proves that the Bible must be the inerrant Word of God. Critics have their counterarguments to all of the above. If we are to know for certain that the Bible is true, we will need a different kind of argument—one that is absolutely conclusive and irrefutable. In all the above cases, we took as an unstated premise that there are certain standards by which we judge how likely something is true. When we stop to consider what these standards are, we will see that the standards themselves are proof that the Bible is true.

Putting it another way, only the Bible can make sense of the standards by which we evaluate whether or not something is true. One such set of standards are the laws of logic. We all know that a true claim cannot contradict another true claim. That would violate a law of logic: the law of non-contradiction. The statements “The light is red” and “The light is not red” cannot both be true at the same time and in the same sense. Laws of logic thus represent a standard by which we can judge certain truth claims. Moreover, all people seem to “know” laws like the law of non-contradiction. We all assume that such laws are the same everywhere and apply at all times without exception. But why is this? How do we know such things?

If we consider the biblical worldview, we find that we can make sense of the laws of logic. The Bible tells us that God’s mind is the standard for all knowledge ( Colossians 2:3 ). Since God upholds the entire universe and since He is beyond time, we would expect that laws of logic apply everywhere in the universe and at all times. There can never be an exception to a law of logic because God’s mind is sovereign over all truth. We can know laws of logic because we are made in God’s image and are thus able to think in a way that is consistent with His nature ( Genesis 1:27 ). So, when we take the Bible as our worldview, we find that laws of logic make sense.

But if we don’t accept the Bible as true, we are left without a foundation for laws of logic. How could we know (apart from God) that laws of logic work everywhere? After all, none of us have universal knowledge. We have not experienced the future nor have we travelled to distant regions of the universe. Yet we assume that laws of logic will work in the future as they have in the past and that they work in the distant cosmos as they work here. But how could we possibly know that apart from revelation from God?

Arguing that laws of logic have worked in our past experiences is pointless—because that’s not the question. The question is: how can we know that they will work in the future or in regions of space that we have never visited? Only the Christian worldview can make sense of the universal, exception-less, unchanging nature of laws of logic. Apart from the truth revealed in the Bible, we would have no reason to assume that laws of logic apply everywhere at all times, yet we all do assume this. Only the Christian has a good reason to presume the continued reliability of logic. The non-Christian does not have such a reason in his own professed worldview, and so he is being irrational: believing something without a good reason. The unbeliever has only “blind faith” but the Christian’s faith in the Bible makes knowledge possible.

The Foundation of Science

Another standard we use when evaluating certain kinds of claims is the standard of science. The tools of science allow us to describe the predictable, consistent way in which the universe normally behaves. Science allows us to make successful predictions about certain future states. For example, if I mix chemical A with chemical B, I expect to get result C because it has always been that way in the past. This happens the same way every time: if the conditions are the same, I will get the same result. Science is based on an underlying uniformity in nature. But why should there be such uniformity in nature? And how do we know about it?

We all presume that the future will be like the past in terms of the basic operation of nature. This does not mean that Friday will be exactly like Monday—conditions change. But it does mean that things like gravity will work the same on Friday as they have on Monday. With great precision astronomers are able to calculate years in advance the positions of planets, the timing of eclipses, and so on—only because the universe operates in such a consistent way. We all know that (in basic ways) the universe will behave in the future as it has in the past. Science would be impossible without this critical principle. But what is the foundation for this principle?

According to the biblical worldview, God has chosen to uphold the universe in a consistent way for our benefit.

The Bible provides that foundation. According to the biblical worldview, God has chosen to uphold the universe in a consistent way for our benefit. He has promised us in places such as Genesis 8:22 that the basic cycles of nature will continue to be in the future as they have been in the past. Although specific circumstances change, the basic laws of nature (such as gravity) will continue to work in the future as they have in the past. Interestingly, only God is in a position to tell us on His own authority that this will be true. According to the Bible, God is beyond time,6 and so only He knows what the future will be. But we are within time and have not experienced the future. The only way we could know the future will be (in certain ways) like the past is because God has told us in His Word that it will be.

Apart from the Bible, is there any way we could know that the future will be like the past? So far, no one has been able to show how such a belief would make sense apart from Scripture. The only nonbiblical explanations offered have turned out to be faulty. For example, consider the following.

Some people argue that they can know that the future will be like the past on the basis of past experience. That is, in the past, when they had assumed that the future would be like the past, they were right. They then argue that this past success is a good indicator of future success. However, in doing so, they arbitrarily assume the very thing they are supposed to be proving: that the future will be like the past. They commit the logical fallacy of begging the question. Any time we use past experience as an indicator of what will probably happen in the future, we are relying on the belief that the future will be (in basic ways) like the past. So we cannot merely use past experience as our reason for belief that in the future nature will be uniform, unless we already knew by some other way that nature is uniform. If nature were not uniform, then past success would be utterly irrelevant to the future! Only the biblical worldview can provide an escape from this vicious logical circle. And that is another very good reason to believe the Bible is true.

We Already Know the God of the Bible

Since only the Bible can make sense of the standards of knowledge, it may seem perplexing at first that people who deny the Bible are able to have knowledge. We must admit that non-Christians are able to use laws of logic and the methods of science with great success—despite the fact that such procedures only make sense in light of what the Bible teaches. How are we to explain this inconsistency? How is it that people deny the truth of the Bible and yet simultaneously rely upon the truth of the Bible?

The Bible itself gives us the resolution to this paradox. In Romans 1:18–21 the Scriptures teach that God has revealed Himself to everyone. God has “hardwired” knowledge of Himself into every human being, such that we all have inescapable knowledge of God. However, people have rebelled against God—they “suppress the truth in unrighteousness” ( Romans 1:18 ). People go to great lengths to convince themselves and others that they do not know what, in fact, they must know. They are denying the existence of a God who is rightly angry at them for their rebellion against Him.

But, since all men are made in God’s image, we are able to use the knowledge of logic and uniformity that He has placed within us,7 even if we inconsistently deny the God that makes such knowledge possible. So the fact that even unbelievers are able to use logic and science is a proof that the Bible really is true. When we understand the Bible, we find that what it teaches can make sense of those things necessary for science and reasoning. God has designed us so that when believers read His Word, we recognize it as the voice of our Creator ( John 10:27 ). The truth of the Bible is inescapably certain. For if the Bible were not true, we couldn’t know anything at all. It turns out that the worldview delineated by the Bible is the only worldview that can make sense of all those things necessary for knowledge.

Conclusion

The truth of the Bible is obvious to anyone willing to fairly investigate it. The Bible is uniquely self-consistent and extraordinarily authentic. It has changed the lives of millions of people who have placed their faith in Christ. It has been confirmed countless times by archaeology and other sciences. It possesses divine insight into the nature of the universe and has made correct predictions about distant future events with perfect accuracy. When Christians read the Bible, they cannot help but recognize the voice of their Creator. The Bible claims to be the Word of God, and it demonstrates this claim by making knowledge possible. It is the standard of standards. The proof of the Bible is that unless its truth is presupposed, we couldn’t prove anything at all.8