Stellvertretung" is a German term with no exact English equivalent. It covers, one might say, the space between representation and substitution. Parents act in substitution for their children, but do so not to replace them, but in their favour. Friends act likewise, as do lovers. Most obviously, humans live by acts of "Stellvertretung". Martin Hailer's work covers a number of fields of: love, friendship, teaching/learning, and intercessory prayer. Moreover, he asks for the divine roots and reasons for human "Stellvertretung". Biblical passages such as Leviticus 16 (Day of Atonement) and Romans 3:21-25 (Jesus Christ as sacrifice of atonement) are in the focus of Hailer's interest. Hailer argues that atonement is not the only way to speak of "Stellvertretung", but that its theological logic is indispensable for a theological anthropology based on christology.