Focusing on the Christian concept of sin, this chapter explores the way in which Anti-Climacus in Part Two of The Sickness unto Death analyzes the concepts of despair, selfhood, spirit, sin, offense, faith, paradox, and God from the standpoint of a Christian understanding of these concepts in contrast to that of classical paganism and Christendom, especially the way in which these concepts are rooted scripturally in Christianity in not willing or doing what is right rather than not knowing or understanding what one should do, as in paganism. It focuses in particular on the Christian doctrine of hereditary sin and the paradox that sin is not a negation but a position before God that cannot be comprehended but must be believed through a revelation from and relation to God, thereby creating the possibility of offense.