Book excerpt: "In this first volume of Sin, Grace and Free Will, Matthew Knell embarks on a journey through centuries of Christian thought, from the Apostolic Fathers to St Augustine of Hippo. While the themes of sin, grace and free will are familiar to any Christian, Knell provides a comprehensive overview of how people such as Irenaeus, Gregory of Nazianzus and Augustine explored these ideas, following the development of early church philosophy on topics such as the problem of evil and the crucial difference between conscious and unconscious sin, as well as the distinction between body and soul. An indispensable primer for any beginning scholar, Sin, Grace and Free Will presents the writings of Christian thinkers of the early church in context and examines the progress of church doctrine from the nascent model of sin in the Shepherd of Hermas to Origen's analysis of divine influence on human will and Augustine's seminal work on grace and salvation."