As a result of the neo-patristic movement of the early twentieth century, the teachings of original sin and atonement as understood in the West were questioned and reformulated based on what was believed to be early Eastern Christian patristic thought. This new paradigm proposed that humanity inherited death and corruption, but not sin, from Adam and that the purpose of the incarnation and salvific work of Christ was to restore humanity from death and corruption, but not an inherent sinfulness. In contrast to this popular and seemingly dogmatic paradigm and false dichotomy between Western and Eastern teaching on sin and redemption, this book proposes that the writings of many Eastern fathers of the early fifth century incorporate many, if not the majority, of the terms and teachings behind what have been labeled as Western departures concerning the relationship between Adam?s sin, humanity, and its redemption in Christ. Through a comprehensive analysis of the writings of Cyril of Alexandria and some of his contemporaries in the early fifth century East during the time of the Pelagian controversy, this book demonstrates that a central and consistent theme of their soteriology revolves around the sinfulness and guilt of all humanity that is rooted in Adam?s sin and is resolved only through recapitulation into the new root, the second Adam, the impeccable Christ. Christ?s impeccability is necessary to correct the state of sinfulness and guilt in humanity through his incarnation and spotless sacrifice on the cross as a ransom and substitute on behalf of and in exchange of all to satisfy the divine justice and to restore humanity to its original state in the divine image.