Spiritual But Not Religious

Robert C. Fuller writes,

Before the 20th century the terms religious and spiritual were used more or less interchangeably. But a number of modern intellectual and cultural forces have accentuated differences between the “private” and “public” spheres of life. The increasing prestige of the sciences, the insights of modern biblical scholarship, and greater awareness of cultural relativism all made it more difficult for educated Americans to sustain unqualified loyalty to religious institutions. Many began to associate genuine faith with the “private” realm of personal experience rather than with the “public” realm of institutions, creeds, and rituals (Spiritual, But Not Religious).

What might be some of the positive aspects of “public” faith?