In this editorial, David Powlison addresses the issue of biological psychiatry, that biology is determinative. Powlison encourages the reader to remember two key arguments. First, what God has said about human nature is always true, and Christianity is the only true and enduring “grand unifying theory” of people, problems and change. Second, this is the third major biopsychiatric wave in the past 130 years (1865-1910; 1940-1960). Like in the earlier waves, new knowledge of localized brain functions and new medical treatments lead to bold claims. Powlison concludes that biblical counselors have work to do to clarify or practical theology of mind-body relations.