About Jack Kettler Jack Kettler is a Reformed Presbyterian layman and Christian apologist who formerly served as a ruling elder in the Orthodox Presbyterian Church (OPC). He and his wife Marea currently attend the Westminster, Colorado congregation of the Reformed Presbyterian Church of North America (RPCNA). With a long career spanning over 37–39 years in corporate America, Kettler built a successful global business in the nutritional supplements industry and holds certifications as a Nutritional Wellness Consultant. He maintains the conservative website Undergroundnotes.com and the theology blog TheReligionThatStartedInAHat.org, where he publishes articles on theology, philosophy, and politics. His writings have also appeared in publications such as the Chalcedon Report and Contra Mundum. Kettler is a prolific author whose works focus on defending Reformed theology, biblical apologetics, critiques of other religions or movements (especially Mormonism), and practical Christian topics. His best-known book is The Religion That Started in a Hat: A Reference Manual for Christians Who Witness to Mormons. Other titles include The Five Points of Scriptural Authority: A Defense of Sola Scriptura, Studies in Soteriology: The Doctrines of Grace Magnified, Doctrinal Disputations, Christian Apologetics in the Marketplace of Ideas, volumes in the What Does the Bible Say? series, A Sampling of Heresies and Theological Errors, Romans 13 and the Limits of Submission to Un-godly Rulers, A Biblical and Scientific Case for Geocentrism, and A Selection of Book and Film Reviews. He has authored or compiled roughly 14–29 titles depending on how collections and editions are counted.