In 2006, a Metal Mass—a regular Lutheran mass with accompanying metal music—was celebrated in Helsinki and created a controversy on several online forums. On the one hand, the focus was the appropriateness of metal music in the context of a Christian mass. On the other hand, the issue at stake was the appropriateness of Christianity in the context of metal music and culture. In this article, we concentrate on how the controversy over the boundaries of ‘good’ religion is constructed in discourse about the appropriateness of metal music in the context of a national church and its services. We argue that the controversy over the Metal Mass is a case of broader negotiation between the function and performance of religious actors in contemporary Finland, yet when it happens within a secularized context, the temporarily full pews turn out to be an anomaly rather than a sign of revival.