C.S. Lewis's The Problem of Pain was first published in 1940.
The book is a work of Christian apologetics addressing why suffering and evil exist if God is good and powerful. Lewis discusses divine goodness, human freedom, punishment, pain, and the possibility of hell. It was written as a theological argument rather than as a personal memoir.
The Problem of Pain appeared during the Second World War, when questions about suffering had immediate public force. Lewis's later wartime broadcasts, which became Mere Christianity, reached a broader radio audience, but the two works are separate books with different origins.
Readers sometimes confuse The Problem of Pain with A Grief Observed, which Lewis published in 1961 after Joy Davidman's death. The earlier book considers suffering in general and attempts a philosophical and theological explanation; the later work records the personal experience of mourning and doubt. The 1940 publication date places The Problem of Pain before Lewis's best-known BBC talks.