As the percentage of unaffiliated seekers or Spiritual But Not Religious people or "Nones" increases in America and in the world at large, a sizable number are drawn toward a spirituality of Nature. And while many of these seekers emphasize simply the physical challenge and ignore the theological or philosophical aspect of their relationship to Nature, "Expanse of God, Caress of Sophia: An Introduction to Wilderness Christian Mysticism" seeks to offer a spiritual / theological interpretattion for those who want it. In the process, it employs insights and meditation practices gleaned from an ancient tradition - that of Christian Mysticism - and updated in a modern context. Special attention is given to John Muir as a Wilderness Christian mystic. "Expanse of God, Caress of Sophia" offers a balanced theology of both Sacred Masculine (Father, Son and Holy Spirit) and of the Divine Feminine (Mother, Daughter and Holy Soul) as a di-polar creative Source in its articulation of a mystical spirituality of Nature. Several chapters are devoted to the qualities of the Sacred Masculine (as opposed to toxic masculinity) and to the transmutation of male sexuality.