What is the primary theme of oratorios as compared to operas?

Oratorios primarily focus on religious themes, which distinguishes them from operas that often explore secular narratives. These concert works are typically based on biblical stories or sacred texts, aiming to convey spiritual messages or narratives through music. They are designed for performance in a concert setting rather than on a theatrical stage, emphasizing vocal and instrumental expressions of faith, devotion, and narrative drawn from religious traditions. This focus on spirituality and worship serves as the foundational element of oratorios, making them distinct in purpose and thematic content from the typically dramatic and secular stories found in operas.