Updated: Jun 3
A sample from the new book: What Christians Believe And Why We Believe It – due for public release in August 2023
Christians believe that people CAN know what is true and what is false.
John 8:32 (NLT)
And you will know the truth, and the truth will set you free.
A common thought today is that there is no such thing as truth because everyone has their own idea about what is true. This idea, however, defeats itself. After all, if there is no such thing as truth, then the statement “there is no such thing as truth” cannot be true! If the statement is true, then at least one thing is true (this statement) and that shows that the statement is false since it is true – which is totally crazy! If it is false, then just saying “there is no such thing as truth” is saying exactly nothing.
Of course, some people think there is no such thing as truth only when it comes to your personal preferences – especially about moral issues. People who pretend an ungodly lifestyle is okay, try to make truth into something relative. They don’t want to believe that truth is a standard whether you prefer it or not. For example, they might say “it may be true for Peter Piper that he loves to eat boiled asparagus on Tuesdays, but that’s not true for me. This means truth is relative to the person.” But this comparison doesn’t show that truth is relative at all because it is still true that Peter Piper loves to eat boiled asparagus on Tuesdays, even if you or I don’t. These two statements do not show a difference in truth, only a difference in preference between you and me and Peter Piper. This means that truth is explaining something in a way that matches the way things really are and that is true whether you prefer it to be true or not.
Christians believe that people can know what is true and what is false in a real way. This is important to Christians because truth explains how things really are. Christian beliefs make serious truth claims that can influence what people decide to do in life. For example, we believe the God described in the Bible exists. We believe every human being will one day answer to God about how he or she lived during life. So, either it is true that the God of the Bible exists – or it is not true. If it is not true, then whatever Christians say about God and what God wants from people has no meaning. If it is true, it is the most important thing in the universe to understand.
People have tried different ways to describe truth and different ways to decide what is good and bad. Every human culture in history has had some form of religious belief that supposedly makes sense out of truth, and these beliefs must be either true or false. They cannot all be true at the same time and in the same way because these religious beliefs all contradict each other. For example, some religions teach that all religious beliefs will lead a person into a true relationship with God or with ultimate reality. Other religions teach that there is only one way to have a relationship with God and all other religious ideas are false. Obviously, at the same time, it cannot be the truth that all ways lead to God and the truth that only one way leads to God. One of these two ideas will match how things really are and the other will not. That’s the nature of truth and Christians believe all human beings can find out what is true.
Knowing what is true and what is false is a central belief for Christians. We think our beliefs about God, about right and wrong and about the meaning of human life are true and other ideas that contradict what the Bible teaches are false. We believe, for example, that the God described in the Bible (the theistic God) really exists. We believe God made the universe using His own power and intelligence and since God is the Creator, He alone has the right to decide how the universe should operate. He alone has the power to create the laws to keep the universe going also but this means God has the power to intervene from the outside into the normal flow of nature. Whenever God does this, it is a miracle. Now, the Bible does teach that miracles are rare, so we should expect the normal laws of nature to keep going day by day most of the time, but we do believe in miracles. We believe miracles are works of God that He uses to communicate with us, so miracles are important to Christian beliefs. This is one reason the belief that people can know what is true and what is false is so important to Christians because if it is true that the theistic God exists then it follows that miracles are things God is able to do.
The most obvious miracle is the creation of the universe itself. This is so because the evidence in nature and science shows that before the universe suddenly began to exist, there was nothing – no energy, no space or time, not even natural laws like the law of gravity. This is a problem because nothing cannot do anything since it is nothing. Only a miracle of the Biblical God, who is eternal and outside of the physical universe, makes sense of the universe coming out of nothing.
The Bible teaches that miracles are rare, but how can anyone really know if the theistic God exists, and miracles are possible if no one can really know anything for sure in the first place? There are ancient religions that billions of people follow, such as Vedanta Hinduism and many New Age religious beliefs, that teach that the world is really an illusion, and no one can really know anything. These beliefs share the idea that truth is relative to the person and since the world is an illusion, miracles are also an illusion. These beliefs contradict Christian’s beliefs so both ideas cannot be true at the same time.
Certain forms of Buddhism, New Age teaching and Hindu belief is that God or ultimate reality is not separate from people in the first place which is the reason everything is really an illusion. They think you and I, rocks and trees, stars and planets are all “god” in some sense. This idea is called pantheism. From this belief comes the idea that evil and suffering are illusions so there is no absolute truth about evil. People only suffer in this life or think that evil is real because they become attached to temporary things such as being popular or having a lot of money. Not getting what you want or losing temporary things creates the illusion of evil in your mind. The trick is to not to get attached to anything by believing that everything is an illusion. That way, when things don’t go as you might want, you won’t feel any suffering. But are these ideas true or not? Do these beliefs line up with how things really are?
The basic problem with these ideas is that if everything is an illusion, you could never know it because you are living in an illusion! If you can’t know anything for certain, then you can’t know that you can’t know anything for certain! Besides, people who believe and teach these ideas show by their actions that they don’t really believe it. For example, if a New Age teacher says that everything is an illusion, doesn’t he expect the listener to believe what he is saying? If he expects the listener to believe everything is an illusion, then what he is teaching is also an illusion that no one should believe. That doesn’t make sense. C.S. Lewis described it this way when he wrote,
If the whole universe has no meaning, we should never have found out that it has no meaning; just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be a word without meaning. 
Many people who say you cannot know what is true don’t always live by these beliefs day-to-day. The truth is people generally recognize in their hearts that some things are true and other things are false. For example, most people tend to look both ways when they cross a busy street even if they say they believe Hindu or Buddhist ideas about everything being an illusion. They do this because it is true that a fast-moving car will crush you if it hits you. If everything is an illusion, then cars must be illusions also, so why worry about a car hitting you? If you don’t really exist because you are really god, the way pantheism teaches, then how can you learn anything anyway? How can you learn that everything is an illusion since learning means changing from not knowing something to knowing something – and to know something means to accept it as true rather than an illusion. Besides, if you are really god then you should already know everything.
Christians believe that individual things or creatures in nature are not God (as in pantheism) because the Biblical God is outside, or transcendent, to the creation that He made. Christians believe God gave us our senses so that we can know what is right and wrong, what is real and what is good and bad. This means that what we see, hear, taste, touch and smell is all real. There is such a thing as truth and human beings can know it. Now, it is truth that our senses cannot tell us everything and no one except God can know everything. It is also true that some people can be deceived or wrong about what they think is real or good or bad, but we can know enough to make sense out of what is true and false. We can know this because while our senses are not perfect, we can compare what we learn from our senses with other facts and from what God reveals to us through the Bible. We can figure out what is true. We can’t know everything, but we can perceive that what is true is that thing or idea that lines up with the facts. This is what Christians believe.
 C.S. Lewis, Mere Christianity, 39.