The researcher conducted an in-depth descriptive study of a church-based ESL program, with ecological perspectives on language learning as the theoretical framework, and an embedded single case study as the research method. The study first examined the program as a whole by focusing on the role of the Christian religion in constructing a special educational space. It then investigated the perspectives of adult immigrant and international learners concerning their learning experiences. Finally, it explored how these adult students' learning experiences have impacted their parental involvement and social participation. The findings of the study demonstrate that relational evangelism and servant evangelism function in forming a nurturing learning community in the program. The adult learners reach a consensus on the program's success in meeting their linguistic and social needs. They acknowledge that the program has played an important role in improving their communicative language skills and social adaptation. Their learning experiences in the program have helped them more actively involve themselves in community participation and their children's education. The study is an attempt to bridge the gap in the field of research about church-based ESL programs. It proposes that future research pay more attention to the special learning context of and expertise within nonformal educational institutions.