What was the title of C.S. Lewis’s 1940 book defending Christian belief against suffering and evil?

C.S. Lewis’s 1940 book defending Christian belief against suffering and evil was The Problem of Pain.

The book addresses a classic theological question: how suffering can exist if God is both good and powerful. Lewis discusses divine goodness, human freedom, punishment, animal pain, and the Christian understanding of heaven and hell.

The Problem of Pain is an apologetic work, meaning that it presents reasons for belief and responds to objections. It is not a personal diary of grief. That distinction matters because Lewis later wrote A Grief Observed from the very different perspective of someone experiencing bereavement directly.

Lewis published The Problem of Pain during the Second World War, when questions about suffering had immediate public force. Its argument is systematic and intellectual, whereas some of his later writing is more autobiographical and emotionally exposed.