Moltmann wrote the Crucified God (1974, English translation) in reaction to certain (specifically N. American) misunderstandings of his earlier work, Theology of Hope (1965). Moltmann's chief concern in The Crucified God was to rescue the hope of the resurrection from any confusion with the officially optimistic culture of modern capitalist society. He does this by reminding his audience that it is only the one who is "unsuccessful" and who suffers with the victims of so-called "success" and "power" that is raised by God at the end. Moltmann's treatment of the cross, therefore, is a plea for Christians to enter into the suffering that God has already entered into, and not remain passive or complacent as outside, "objective" (i.e., apathetic) observers of the human condition. If God does not remain above the plane of history dispassionately observing the suffering of the Son on the cross, but is radically "in Christ," involved in and affected by that suffering (God loses an only child!), then we too (as followers of God) must enter into the suffering of our victims (Holocaust, Third World poverty, etc.). In this respect, the cross becomes the critique ALL utopian dreams (socialist, capitalist, facist alike). Resurrection hope is hope for the hopeless, for the crucified ones of this world.
Moltmann has not only boldly reformulated Luther's "Theology of the Cross," but has, in the process, also made an enduring contribution to Political and Liberation Theology.