The relationship between ideas and history is important in order to understand the past and the present. The idea of religious liberty and the realization of that ideal in sixteenth-century Europe by the Anabaptists in Switzerland and South Germany in the 1520s was considered to be revolutionary in a society characterized by the union of church and state. The main impetus of the idea of religious liberty for the Anabaptists was the application of the New Testament standard of the Christian church, which was an independent congregation of believers marked only by adult baptism. The purpose of the present study is to demonstrate the contributions of the Swiss Anabaptists to the idea of religious liberty by looking at the ministries and activities of three major leaders of the early Swiss movement: Conrad Grebel, Michael Sattler, and Balthasar Hubmaier. This thesis takes up the modern form of religious liberty as analyzed by twentieth-century authorities, as a framework for better understanding the contributions of the Anabaptists. My research then explores the establishment of the first Anabaptist church in history, the Zollikon church outside of Zurich, and examines its organization membership, motives, and strategies for evangelizing Switzerland. In all areas influenced by the Anabaptists, there was considerable acceptance of their doctrine of a separated church. Their teaching on liberty of conscience also influenced people in towns such as Zollikon and Waldshut. Possible historical links between the Anabaptist doctrines and establishment of later Baptist denominations are shown.