In the eighteenth century, dramatic electrical performances were favourite entertainments for the upper classes, yet the therapeutic uses of electricity also reached the lower strata of society. This change in the social composition of electrical audiences attracted the attention of John Wesley, who became interested in the subject in the late 1740s. The paper analyses Wesley's involvement in the medical applications of electricity by taking into account his theological views and his proselytizing strategies. It sets his advocacy of medical electricity in the context of his philanthropic endeavours aimed at the sick poor, connecting them to his attempts to spread Methodism especially among the lower classes. It is argued that the healing virtues of electricity entailed a revision of the morality of electrical experiment which made electric sparks powerful resources for the popularization of the Methodist way of life, based on discipline, obedience to established authorities and love and fear of God.