The global ecological crisis has spawned intensive reflection about views of the natural world. Western Christian thought has received special scrutiny as modern alienation from nature has been traced to Christian theology. Undiscovered within the mystical theology of medieval Christian theologian Nicholas of Cusa lies an ecologically promising vision of nature. The concept of divine immanence presented by this medieval thinker provides a rich spirituality that is inclusive, rather than exclusive, of the natural world. It is also far more intimate than contemporary stewardship theology. Cusanus interprets theophany as divine self-expression. A series of striking metaphors, including God's enfolding and unfolding, God as "Not-other", and Christ as the contracted maximum, reveals a holistic spirituality. Nicholas of Cusa's concept of divine immanence infuses the world with immeasurable value and gives rise to a Christian theology that can address the current ecological crisis.