This dissertation argues that the modern U.S. Supreme Court's religious liberty jurisprudence is incoherent because its free exercise jurisprudence, which sometimes requires religion to be shown favor through various accommodations, clashes with its establishment clause jurisprudence, which forbids the state from favoring religion. The instability of the court's religious liberty precedents manifests itself in the inability of the current court to agree on a clear approach reconciling the two religion clauses.One reason for the current contradictory approach is that there was no consensus about the juridical meaning of religious liberty at the time of the Founding or of the framing of the First Amendment's religion clauses. While the Founders generally agreed that there was a natural right to religious liberty, they disagreed about how much government should accommodate religion from otherwise valid laws. They also disagreed about the extent to which government could support religion and religious institutions.Given the unsettled nature of American religious liberty jurisprudence, this dissertation proposes looking to the Federal Constitutional Court of Germany's religious liberty jurisprudence for more insight. The dissertation argues that the German court shows how various aspects of the freedom of religion can be judicially interpreted in a more coherent way. The Federal Constitutional Court has interpreted its analogous constitutional protections for religious liberty to require the state to show favor to the religious and ideological life of the nation's citizens. Therefore, the German court does not forbid government from showing favor to religion in general, so it avoids a contradiction with its generous approach to religious accommodations. This dissertation argues that the German court's interpretation is superior, even apart from its internal consistency, and that the American court would be well advised to adopt an approach more like the German Constitutional Court.