This paper analyzes how presidential candidates Fabricio Alvarado and Nayib Bukele used Facebook during the elections in Costa Rica (2018) and El Salvador (2019) respectively to develop a particular style of communication that blended populist elements and religious discourse. This style of communication extended traditional modes of populism that have prevailed in Latin America since the turn of the century (emphasizing the notion of the hero who comes to rescue “the people”) but expressed them in an explicitly religious way (stressing the role of a “messiah” who comes to alter the established political order). We conducted both content and multimodal discourse analyses of 838 posts made by these candidates on Facebook during their respective electoral campaigns. We argue that the study of these campaigns would be incomplete without accounting for the relationship between populism, religion, and social media. While populism gave political validity to religious discourse, a religious imaginary provided populism with charismatic and messianic authority. This populist/religious reason found an ideal expression in Facebook and, simultaneously, was resignified by this platform's affordances. In this way, we assess how fundamentalist Christianity has become a legitimating force of knowledge and politics in the context of epistemic tensions that shape contemporary Latin-American societies.