Isaiah's Leper is the result of more than thirty years of research concerning the relationship, or lack thereof, between the teachings and actions of Jesus of Nazareth and the teachings and actions of the Roman Catholic Church.

Dr. George Daniel O'Clock, Jr., encourages readers to think about what Roman Catholicism was and is, compared with what it claims to be. Isaiah's Leper also raises numerous questions concerning the state of the Roman Catholic Church today. It is predominantly focused on Roman Catholicism, but O'Clock also shows that the conflict and concerns addressed are applicable to all forms of religious belief systems.

Isaiah's Leper identifies some of the actions and attitudes of the Roman Catholic Church that are the antithesis of the Christ's teachings. It also identifies what has to be stripped from the Catholic Church in order to save it from its own corrupt origins.