Since the end of the Cultural Revolution and the beginning of the Reform and Opening Up period, Protestant Christianity in Mainland China has grown rapidly, comprising a denominationally diverse array of both state-registered churches (regulated by the Three-Self Patriotic Movement) and “underground” communities (often referred to as “house churches”). Despite continued crackdowns on Christian activity by the state, the past decade has seen Christianity being increasingly recruited to conversations about national flourishing, and religion's role in the production of "quality" Chinese citizens in a context of national growth. Based on fieldwork among both state-authorized and underground Christian churches in Nanjing, along with several other sites in the Yangtze River Delta’s aspirational “global city cluster," this dissertation examines the imbrications between state projects of population reform and Christian practices of conversion, church-building, and community-making. I argue that the congruity between state discourses of citizen “quality” and Christian projects of conversion conceals the ways religious life internally produces the potential for critique and counter-conduct, even when mobilizing the same grammars of reform. I show this by analyzing how the discourse of “quality” animates particular labors of reformation in everyday contexts of Christian community building. These contexts range from urban house churches that develop ways of “making families” that are noncompliant with population-management policies; to clandestine Christian schools that reject nationalized regimes of evaluation; to Christian public works projects that deploy discourses of “quality” while simultaneously laboring to differentiate spiritual health from the language of material prosperity. Across these sites, I show the different ways in which Christian communities reflect and refract state discourses on aspiration, mobility, class, and the cultivation of global citizens.