Welsh jurist and Anglican theologian Norman Doe has pioneered the modern study of comparative “Christian law” – analyzing the wide variety of internal religious legal systems governing Catholic, Orthodox, and Protestant churches worldwide. For him, law is a fundamental but underutilized instrument of Christian identity, denominationalism, and ecumenism, and he shows the many areas of overlap and collaboration even within and between Christian traditions that have sharp differences on other matters. This Article offers an appreciative analysis of the development of Professor Doe’s scholarship, and situates his work within the broader global field of law and religion studies.