Which 1940 C.S. Lewis book defended Christian belief against objections?

The Problem of Pain is C.S. Lewis’s 1940 book defending Christian belief against objections.

The book addresses the problem of suffering: how pain and evil can exist if God is good and omnipotent. Lewis discusses human freedom, divine goodness, hell, animal pain, and the purpose of suffering from a Christian philosophical perspective.

It was published during the Second World War, when questions about suffering and evil had particular urgency. Lewis’s approach is argumentative and theological rather than autobiographical, and the work reflects his interest in making Christian ideas accessible to general readers.

The book is often confused with Mere Christianity. Mere Christianity grew out of wartime radio talks broadcast by the BBC and presents core Christian beliefs, while The Problem of Pain is a distinct earlier volume focused specifically on suffering.