In The Problem of Pain, C.S. Lewis focused on solving the intellectual problem raised by suffering (Lewis, The Problem of Pain, 32). The problem of pain has caused both believers and unbelievers to not only question the goodness of God but also His power. Lewis revealed an assumption that is shared by many: "If God were good, He would wish to make His creatures perfectly happy, and if God were almighty, He would be able to do what He wished. But the creatures are not happy. Therefore, God lacks either goodness or power, or both” (Lewis, The Problem of Pain, 224).
Lewis challenged such thinking by first defining the Omnipotence of God. Lewis states, “His Omnipotence means power to do all that is intrinsically possible, not to do the intrinsically impossible. You may attribute to Him miracles, but not nonsense. This is no limit to His power” (Lewis, The Problem of Pain, 243). Lewis believed that it was crucial to start with a right understanding of God’s Omnipotence because human reasoners often make mistakes, either by arguing from false data or by inadvertence in the argument itself (Lewis, The Problem of Pain, 256). Hence, man’s faulty assumptions about God are mainly caused by his inability to define true goodness and power.
Lewis also argued that God’s idea of “goodness” is different from ours (Lewis, The Problem of Pain, 373). He believed that when we truly understand God’s goodness, we will know His love that desires our salvation and transformation. Lewis notes, “Love may forgive all infirmities and love still in spite of them: but Love cannot cease to will their removal” (Lewis, The Problem of Pain, 468). To understand the problem of pain and the depth of God’s love, Lewis also saw the need to explain human wickedness (chapter 4) and the fall of man (chapter 5). Lewis states, “Christianity has to preach the diagnosis—in itself very bad news—before it can win a hearing for the cure”. (Lewis, The Problem of Pain, 576)
From explaining man’s condition, Lewis then proceeded to man’s possible destinations (heaven or hell). Lewis affirmed the reality of hell. He explained that God’s justice demands a place of torment for the unrepentant. He argued that to object the doctrine of hell was to deny our sense of justice in the world. He closes with a chapter on heaven to remind the believer that pain is a momentary experience and that he can look forward to a world that is free from pain and full of God’s presence.
In Christian Apologetics, Lewis sought to defend Christian doctrine in a way unscholarly people could understand (Lewis, God in the Dock, 199). Lewis gave insightful strategies on how Christians can respond to scientific attitudes towards Christianity or to political and philosophical issues. By presenting their views and how they can be refuted, Lewis urged his readers to learn the language of their audience so that they can present timeless truths compellingly and persuasively.