Service-learning is an important and effective educational pedagogy that has grown tremendously in Spain. Research shows that service-learning has positive effects on the professional and personal development of future teachers. Since future teachers, in turn, influence the education of the next generation, it is important to understand how service-learning may influence the life purposes of student-teachers themselves, specifically, how emotions influence this development process. Statistical analyses of 198 Madrileño student-teachers' responses to online questionnaires suggested that service-learning involves positive emotions like interest, enthusiasm, inspiration and determination. Surprisingly, these positive emotions "decrease" during service, except for the 53 student-teachers whose purposes changed. Most reported positive changes in all dimensions of life purpose, with some also noting strengthened "relationships" between 10 pairs of dimensions, such as between stronger impetus to help others and a clearer understanding of who would benefit. This study supports teaching as a calling and how service-learning can strengthen that calling.