[This post concludes the series on Logic and Apologetics]

Logical fallacies are flaws in reasoning that superficially seem to be sound, but upon examination are found to be false. The power of logical fallacies is that even after they have been shown to be flawed, they still retain their power to convince because they are often emotionally satisfying.

  1. Begging the Question—assuming a conclusion to be true without proving it. If I am trying to prove that people have lost the ability to distinguish between right and wrong by citing increase numbers of adulterous affairs and abortions, I am assumingadultery and abortion to be wrong, when I should have to arguethat they are wrong. Even though adultery and abortion are wrong, rising incidents of each does not necessarily prove that people have lost the ability to distinguish right and wrong.

How Christians do this:

“I believe the Bible is the Word of God because I just know it to be so.”

“Evolution cannot explain the origin of life on earth, because it is not true.”

How unbelievers do this:

“Science has disproved the existence of God because there is no scientific evidence for God.”

“Jesus cannot be the only way to be reconciled to God, because that would mean all other religions are wrong and most of the world would be condemned.”


  1. Faulty Analogy—making a comparison between two things that are not similar. An analogy allows us to explain one thing by comparison to another. But every analogy breaks down at some point and some things bear no similarity with other things. If I compare the gentleness of a mother with her baby to a nuclear explosion, there is little chance that the analogy will be helpful in any way.

How Christians do this:

“The Trinity is like an apple (or an egg, or water, or a three-leaf clover).”

“If a person is spiritually dead then I won’t bother sharing the gospel with him because dead people don’t hear you when you talk.”

How unbelievers do this:

“Christians used the Bible to support slavery and they were clearly wrong, so when they use the Bible to condemn homosexuality, we can clearly see they are wrongly using the Bible again.”

“Our genetic code is ‘selfish’ and blindly strives to reproduce itself for survival.”


  1. Equivocation—when a word or phrase is used in more than one sense or its meaning changes in the middle of an argument, a dialogue descends into confusion. If I ask my teenager to clean his room and we have two different ideas of what “clean” means, the communication will fail.

How this confusion happens:

Skeptics love to define faith as “belief despite the lack of evidence,” but that is not what Christians mean when they use the word. By “faith” a Christian means trust in God’s revelation. If a skeptic says, “I have evidence and you have faith,” I must correct his erroneous understanding of faith or we will never get anywhere in the discussion.

Similarly, evolutionists often use the word “science” when in fact they believe in scientism(the only things that exist are physical objects and natural, not supernatural, forces guide everything apart from a divine intelligence). If we do not expose the difference, we will find ourselves arguing against science when we have no misgivings about real science.

Hopefully this explanation on logical fallacies has helped you notice some fallacies in your own thinking, as well as building discernment for identifying in the arguments of unbelievers. Skill in detecting logical fallacies takes time and much practice. If you are thinking carefully and critically, however, you will begin to spot fallacies and be able to dismantle them in order to help another person see the truth more clearly.

A Little Note on Logic

Logic is not the final arbiter of all things true, for several reasons. First, flawed and finite people use logic. That means that while logic may help to ensure we arrive at consistency, the premises upon which logical argumentation are built are sometimes disputed. Two rational people can disagree about a premise because even statements of fact are often values-laden. That is, we don’t have a God’s-eye-view of reality without having to interpret what we see. Our own biases, limitations, and errors can creep into our thinking.

Second, logic flows form the character of God. Logic does not stand over God, and therefore some things will not seem logical, even though they are true.


So, what did I say to my friend in Spain? Remember him? He is the one who asked me how to respond to someone who claimed Christianity simply isn’t logical. As we have discussed throughout this book, whenever you don’t know what to say, ask a question. My advice was to ask those who claimed that Christianity was not logical, “Howis Christianity not logical?” There is, in fact, no logical contradiction in Christianity, as we have seen. The fact that it defies human expectations does not make it illogical.

Christians do not need to resort to logical fallacies, because the Christian faith is the summit of wisdom and rationality. To believe and argue logical fallacies demeans and diminishes the true logic of the gospel. Paul states this clearly in 2 Corinthians 4:3-6 where Jesus is presented as the wisdom of God:

And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God. For what we proclaim is not ourselves, but Jesus Christ as Lord, with ourselves as your servants for Jesus’ sake. For God, who said, “Let light shine out of darkness,” has shone in our hearts to give the light of the knowledge of the glory of Godin the face of Jesus Christ.

Everything pursued by the major cultures of the first century Western world was found in Christ. The Greeks sought the light of wisdom, Jews sought knowledge, and the Romans sought glory, and yet each of these is embodied in the message of Jesus. To seek these things apart from Christ is futile, and to claim to have obtained them apart from Christ requires irrationality and contradiction.

Paul also reminds us that the wisdom of God is wiser than the greatest of “human” wisdom that contradicts it (1 Cor. 1:20-25). This does not mean that unbelievers are not or cannot be brilliant in many areas of human achievement. Some of the brightest scientists, philosophers, engineers, writers, and so on have rejected Christ. It does mean, however, that they can never understand the whyof the knowledge they possess. They can never know the purpose for which they and their expertise exist. They can never understand the infinitely glorious spiritual realities of God’s world until they are transformed by Christ. To make sense of the world they must devise strategies and explanations fraught with logical fallacies. These strategies “work” for them, but they are not the truth. Our prayer is that the Spirit of God will give sight to their blind eyes, abandon their resistance to the gospel built on their fallacies, and see clearly the wisdom and rationality that is Christ.