Everything that Jürgen Moltmann writes is worth reading and thinking about, beginning with his Theology of Hope (1964) and its compelling message that Christianity is deeply and essentially about hope—not optimism, but hope based on trust in God’s redeeming activity even in the midst of dreadful circumstances.
Moltmann has written in various places of the personal experience out of which his theology and faith grew. He was a 17-year-old conscript in the German army in 1943, stationed in his hometown of Hamburg, when he witnessed the Allies’ firebombing of the city; it killed 40,000 civilians. Later he was a prisoner of war. Those searing experiences lie behind Theology of Hope and another important book, The Crucified God (1972).