For the first time since its inception, the Congregação Cristã no Brasil (CCB) has lost members – two hundred thousand members in the last decade – while other traditional Pentecostal churches’ membership continue to grow. Based on survey research data, this study explores the diverse views of church members and how institutional factors affect the growth of the church. Two opposing views among church members are identified: fundamentalism and progressivism. Besides providing empirical data, this work engages a wider debate on how the strict nature of the CCB leadership, based on a traditional authoritarian model, is unwilling to adapt to cultural and social changes, giving rise to discontent, tensions, and schisms.