The author mounts a sustained, rational examination of revealed religion, inspecting the Old and New Testaments to challenge claims of supernatural revelation and miracles and to expose contradictions and human authorship. He argues that true religion should rest on reason and the observable laws of nature rather than clerical authority, proposes reforms in education to emphasize practical and scientific knowledge, and offers a natural theology that deduces God's existence from the universe. Discussions extend to cosmology and the folly of priestly deception, concluding with a recapitulation and a call to return to simple, reasoned faith.