The book Need to Know presents a comprehensive and coherent model of responsible Christian thinking. This model is grounded in the Christian theological tradition, but is also informed by a diverse range of thinkers from the history of philosophy, natural science, social science, and culture. The book's approach is practical yet theoretically profound, and it offers a scheme for integrating experience, tradition, scholarship, art, and the Bible into a system of thinking about thinking. At the heart of this approach is a simple yet powerful idea: since God calls human beings to fulfill certain roles in the world, God can be trusted to provide the necessary knowledge for them to do so. This concept of vocation provides both the motivation and the assurance that faithful Christians can rely on God to guide their thinking, on a "need to know" basis. With this approach, Christians can navigate complex decisions, from choosing a career to discerning the best fitness plan, with confidence and clarity.