Interactive cultural practices such as songs and storytelling are key to contemporary social movement organizing because they can attenuate the challenges of social difference by expanding participants' understandings of self and community. Yet the precise cultural dynamics through which such practices become effective are not well understood. Using the case of a large faith-based community organizing coalition, I show that practices focused on personal moral authenticity are especially effective in fostering alignment between social movement goals and individuals' pre-existing moral commitments. I define personal moral authenticity as the ambition to develop, enact, and perform a moral identity that is "true" to an enduring internal self, and validate that identity through interactions with others. This is an effective basis for organizing practices because it spans the various cultures of commitment that prevail in different racial and religious subgroups and gives individuals a personal stake in social change projects. In highlighting how it animates practices in faith-based community organizing, one of the most robust fields of grassroots civic activity in the United States, this article illuminates an important part of the cultural dynamics underlying much contemporary social change work, and specifies how religion contributes to progressive social change efforts amid ongoing religious disaffiliation.