Moll Flanders is one of the most important works of Daniel Defoe,which relates a life story about a picaro female character.As a writer with sharp insight and consciousness,Defoe describes a lonely woman’s struggle for survival in the wilderness.The book not only inspires the readers over the morality values,but also reflects the other side of religion.This paper probes the secularization of Christianity from individual and institutional layers manifested in Moll’s marriages and confession,priests’action and the governess’s confession,which demonstrate the core issues of secularization,that is,materialism,modernity,freethinking and blasphemy.