Logic in Apologetics

Logic is typically very important in apologetics. To defend the faith, the Christian must use truth, facts, and reason appropriately and prayerfully. The Christian should listen to objections and make cogent and rational comments in direct response to the issues raised.

Logic is simply a tool in the arsenal of Christian apologetics. Logic is a system of reasoning. It is the principle of proper thinking used to arrive at correct conclusions. Of course, some people are better at thinking logically than others, and there is no guarantee that using logic to the best of one's ability will bring about the conversion of anyone. After all, logic is not what saves a person. Jesus does that, and we are justified by faith (Rom. 5:1).

Therefore, the proper use of logic in apologetics is to remove intellectual barriers that hinder a person from accepting Jesus as Savior. Logic is not to be looked at as the answer to every problem facing Christianity nor every objection raised against it.  Logic has its limits. It cannot guarantee wisdom. It cannot prove or disprove inspiration or love.  It cannot replace the intuition gained through experience, the prompting of the Holy Spirit, nor the clear truth of God's word.  Nevertheless, logic is still very valuable and can be quite powerfully used by people, both saved and unsaved.

Opponents of Christianity use logic

Sometimes an opponent of Christianity might use logic problems as a type of evidence against God’s existence. Consider this rather basic objection:

  • Proposition: God can do all things.
  • Statement: Can God make something so big that He cannot pick it up? If He can, then He cannot do all things because He could not pick up the rock. If He cannot, then He cannot do all things because He cannot make a rock so big He can’t pick it up.
  • Conclusion: Since God can do all things and we have shown that there are things He cannot do, therefore, God does not exist.

On the surface, this logic could be difficult to answer. But, all we have to do is think a bit more and we can see that the problem asserted above is not logical to begin with. Here's the answer:

  • Proposition: God cannot violate His own nature; that is, He cannot go against what He naturally is.
  • Statement: God's nature does not permit Him to lie, to not be God, etc.
  • Conclusion: Therefore, the statement that God can do all things, is not true and the conclusion raised against God is also not true.

Logic is a valuable tool in witnessing, particularly when using proofs of God's existence.  Consider the following basic approach using logic:

  1. The universe exists.
  2. The universe cannot be infinitely old; because if it were, it would have entered into a state of entropy long ago.
    1. Entropy is the second Law of thermodynamics which states that all things are moving toward chaos and non-usable energy.  In other words, everything is running down.
    2. The universe is not in a state of non-usuable energy; therefore, it is not infinitely old.
      1. If the universe were infinitely old, the universe would have run out of usable energy long ago.
      2. Since the universe is not infinitely old, it had a beginning.
      3. The universe could not have brought itself into existence.
      4. Something before the universe and greater than the universe had to bring the universe into existence.
      5. That something is God.

All logical proofs for God have strengths and weaknesses.  But the Christian should not be afraid to use logic, reason, and evidence when defending the faith.

I suggest getting books on introduction to logic and go through what you can.  Absorb as much as possible.  Also, learn to ask questions in discussions.  Learn to think about what the ramifications are of what people are saying.  Look for logical flaws in their speech and your own.  If it helps to learn from actual dialogues, go to the

Apologetics Dialogues

 page and read some of the actual dialogues I've had with unbelievers.  They should help to see how to "do apologetics," though I have much to learn in this area.

Is logic a common ground between the believer and the unbeliever?

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