This article is the result of a broader research that I have conducted in the Nahua village of Atliaca, Guerrero, since 2011. In the current phase, I study the process of religious diversification in the community. In this paper, I analyze two religious changes driven by Presbyterianism: the adoption of the Bible as the cardinal axis in the expression of believers' faith, and the apprehension of an explanatory model of health and illness that distances itself from traditional healing practices by focusing on the power of God as the only agent capable of healing people. Both cases illustrate in detail the detachment from what is known as el costumbre, particularly in its religious character.
In both areas, I rely on the perspective of believers, both those who are Presbyterian by birth and converts, as a substantial basis for learning and understanding these changes.