Mere Christianity Review

Written by Josiah Nichols

April 10, 2023

Mere Christianity, Cs Lewis, Author

Copyright free image of Mere Christianity by C. S. Lewis from


Mere Christianity Review. Love him or hate him, C. S. Lewis is one of the most well known apologists of the 20th century. He is most well known for his children’s books, The Chronicles of Narnia. Yet, his influence on modern apologetics is astonishing. Many times pastors or apologists cannot go one sermon or speech without quoting him. He has influenced conservative thinkers like Michael Knowles, Matt Walsh, and Candace Owens. If one wants to get his basic views on theism, Christianity, and theology, then one needs to read his book Mere Christianity.


While it is not a long book, it is separated into four books. These books are actually sections covering different aspects of his argument.

The first book covers coming to belief in God through reason. It is called Right and Wrong as a Clue to the Meaning of the Universe:

  • The Law of Human Nature.
  • Some Objection
  • The Reality of the Law
  • What Lies Behind the Law
  • We Have Cause to be Uneasy.

The second book covers What Christians Believe:

  • The Rival Conceptions of God
  • The Invasion
  • The Shocking Alternative
  • The Perfect Penitent
  • The Practical Conclusion

Book Three is Christian Behavior:

  • The Three Parts of Morality
  • The ‘Cardinal Virtues’
  • Social Morality
  • Morality and Psychoanalysis
  • Sexual Morality
  • Christian Marriage
  • Forgiveness
  • The Great Sin
  • Charity
  • Faith
  • Faith

Book four is Beyond Personality: or First Steps in the Doctrine of the Trinity

  • Making and Begetting
  • The Three-Personal God
  • Time and Beyond Time
  • Good Infection
  • The Obstinate Toy Soldiers
  • Two Notes
  • Let’s Pretend
  • Is Christianity Hard or Easy?
  • Counting the Cost
  • Nice People or New Men
  • The New Men

Positive Elements of Mere Christianity

  1. S. Lewis presents a reasonable and logical case for Christianity throughout the course of this book. If one tried to present a case for theism with an atheist audience in mind, Lewis does this in the first section of his book. He does this by appealing to the universal law of morality.[1]

His reasoning can be shown by the following facts. People know there is a sense of oughtness people must live by.[2] People do not live up to this law.[3] This law is the Law of Nature.[4] Those who deny the Law of Nature do not live by that denial.[5] Everyone believes in a right and wrong, whether they acknowledge it or not.[6] This shows the Law of Nature is really there but it points to a reality which is above the human experience.[7] Materialism does not make sense because there would be no universal Law of Nature just mere accidents and chances.[8] This means there is a power, director, or guide calling mankind to live a certain way beyond what can be known by the physical sciences.[9] One can get to know this Someone behind the universe better by studying the moral law over the universal sciences because it is inside information.[10] One can know this is an intelligent person behind this because he is interested in “fair play, un-selfishness, courage, good faith, honesty, and truthfulness.”[11] Therefore, God is good.[12] Christianity makes sense of all of this and provides comfort of being reconciled to this God by repentance and the person of Christ.[13]

There are other positive elements Lewis gives by inductive reasoning to “prove” Christianity. He gives lessons on evidence for the Trinity, Christian morals, etc. Lewis gives a great way of arguing for Christianity.

Negative Elements

In Striving for Eternity’s opinion, Lewis does not present the best way of defending the Christian faith. We believe in presuppositional apologetics, which starts with the God that every person knows exists (Romans 1:18-20) and that He has spoken (the Bible). Thus, we start with the Bible in our apologetic, which is a sword that is alive and active… and judges the thoughts and attitudes of the heart (Hebrews 4:12-13). It cuts down arguments, reveals the truth, and it shows everyone knows there is a God (Romans 1, Hebrews 4:12, 2 Corinthians 10:3-5). Lewis presents a classical apologetic for the Christian faith.

Lewis also presents a view of “free will” not taught in the Bible.[14] The teaching is laced throughout the book for only for mankind’s original state, but also for the state man is in now.[15] He even teaches God can do nothing with man unless he wills it.[16] Our response is: tell that to Nebuchadnezzar, Jonah, and the apostle Paul (Daniel 4, Jonah 1, Acts 9, Romans 1-3).

Who Would Benefit from this book?

That being said, this is an excellent book for those who want to learn how to argue from an inductive standpoint. Most people will listen to your arguments when you start with the evidence before you make your claim. Classical apologetics is also a good tool to have when sharing the gospel if it is used alongside of presuppositional apologetics. The arguments Lewis makes for theism are sound arguments to make against atheists. I would recommend this to high school students with the supervision of their parents. Also, I would recommend this book to college students, teachers, and pastors. It is available on for $12.49 in kindle, $9.99 paperback, and $22.49 hardcover.


  1. S. Lewis was a great thinker. He recognized all reason, knowledge, and morals works its way back to God. God is the foundation and upholder of all reality. He also recognized Christianity was true. It makes sense of all the disorder and chaos in the world. Christianity shows we are to blame for evil. Yet, God also in His mercy sent His Son, the Lord Jesus Christ, to live a sinless life, die on a cross, and rise from the dead to forgive all who repent and trust in Him. Lewis’s book should be read and used, but with a discerning mind, founded on the Scriptures.

Furthermore, if you want more biblical resources on studying the Scriptures, check out the store at There are also a lot of other articles on the website to encourage you to dive deeper into God’s Word. Please also check out Apologetics Live at, where Andrew Rappaport, Dr. Anthony Silvestro, and Justin Pierce answer your questions and teach you how to defend the faith. It is on from 8pm – 10pm EST. Also, do not forget to check out the Rapp Report, where you can hear the teaching of Andrew Rappaport and the Christian Podcast Community. Lord bless you.

[1] C. S. Lewis, Mere Christianity (New York: HarperCollins Ebooks, 2009).

[2] Ibid., 3 – 4.

[3] Ibid., 4.

[4] Ibid.

[5] Ibid., 5- 6.

[6] Ibid.

[7] Ibid., 20.

[8] Ibid., 21 – 35.

[9] Ibid.

[10] Ibid., 27 – 29.

[11] Ibid., 29.

[12] Ibid.

[13] Ibid., 31 – 32.

[14] Ibid. 47 – 49.

[15] Ibid., 202.

[16] Ibid.

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