In this paper, we analyse the short term mission experiences of young UK Christians volunteering in Latin America to explore the relationships between international volunteering, faith and subjectivity. We draw on understandings of global citizenship and cosmopolitanism as processes rather than end points to reveal the contingent and multilayered ways subjectivities evolve and are performed through international volunteering. We particularly explore how faith based and secular imaginaries come together to shape a cosmopolitanism that smoothes over inequality and injustice. We highlight the need to acknowledge the multiple ways global subjectivities are expressed by analysing research diaries kept by the young volunteers. These reveal how volunteers’ negotiation of their faith, public imaginaries of development and everyday encounters with inequality, produce instabilities that have significance for thinking about cosmopolitan sensibilities and global citizenship.