Parents deciding between religious and public schooling face many unknowns. One of the most important factors is how the schools might affect the faith of their children. Yet for all the debates over education, we know little about the effectiveness of Christian education on the spiritual lives of students. Students at religious schools are probably more religious than are public-school students. At issue, however, is why they are more religious. Is it just that they come from more religious families, or does the school itself directly affect the religiosity of teens?