Even though John Wesley claimed that the atonement was crucial to his theology, he never articulated a systematic theory of the atonement. This paper explores the way in which the atonement functions within his theology as the best approach for deciphering his understanding of the atonement as a foundational concept for his moral theology. The cross functions in his via salutis in two ways. It plays a substitutionary role in the removal of sin and guilt and has a participatory function, through the work of the Holy Spirit, to affect holiness in the life of the believer. These aspects of the atonement are seen in his sermons, New Testament Notes, and the hymns he selected.