To Pope John Paul Ⅱ, the problem of evil was historical and the realistic domain at the same time. He observed and experienced the existence of evil firsthand: Ideology of evil such as World War Ⅱ, nacizm, and communism trampled Poland, which was the homeland of Karol Wojtyla and was ingrained in his memory, never removed. Pope John Paul Ⅱ reflected on the problem of evil and tried every possible means for removing it for entire his life. This was the main factor which created his inner characteristics and formed his persona. This study sheds light on the context in which the spirituality of mercy originates through explaining the life of Pope John Paul Ⅱ, who considered the problem of evil. The themes of ‘good and evil’, ‘evil defined as a lack of good’, and ‘the existence of God who is the highest Good’ show how Christian philosophy became the language of faith and how this language became a living spirituality. The tradition of Christian theology and philosophy that sought answers to evil now forms the structure of the spirituality of mercy in the 21st century.