This essay explores the origins and expansion of New England Praying Towns in the context of the ongoing theological and religious debates of 1646–1674. This period spawned significant debates regarding the extent of the Abrahamic covenant, the requirements for church membership, and the nature of conversion. The ministers present at the Synod of 1662 gathered to settle the question of “extended baptism,” an issue where Indian and English concerns intersected. Reformers who promoted a generational vision of church membership emphasized the efficacy of spiritual preparation for younger generations and the power of a broader and more inclusive church covenant. This development benefitted Algonquians living in Praying Towns because theological preparation validated efforts to catechize and instruct Praying Indians in religious matters. Likewise, a broadening vision of church membership enabled some colonists to consider the possibility that Indians might be included within their religious communities. These projects, launched before the formalization of the Halfway Covenant in 1662, presented a tangible example of spiritual preparation in practice and served to validate the conversionary process within the colony at large. English observers found Indian conversion impressive (or reacted with intense skepticism) because most theologians considered Indians unlikely converts, especially in larger numbers. For Algonquians demonstrating an interest in English spirituality, church membership represented a degree of parity with their New England brethren. Tracing the development of New England missions, the pathway to church membership, and the debates on both missions and extended baptism reveals both the possibilities and limits to the inclusion of Indian Christians within New England's religious institutions.