During one of humanity's darkest periods, World War II, C.S. Lewis was invited by the BBC to give a series of radio lectures aimed at explaining the Christian faith in a simple and clear way. Later, adjusted by Lewis himself, this material would give rise to *Mere Christianity*, a great classic of literature. In the most popular and accessible work of his legacy, Lewis presents the main elements of the Christian worldview, gradually leading the reader to deeper and more complex themes, provoking reflection and debate. In this special edition, translated by one of Brazil's leading Lewis scholars, you will find the words that encouraged and strengthened thousands of listeners during wartime and still resonate more than 70 years later.