Membership in Opus Dei requires a supernatural vocation. It is a personal call from God to place one's whole life at his service, spreading the message of the universal call to holiness in ordinary work and social life. Members join by a contractual commitment rather than by vows, and remain ordinary faithful of their dioceses.
This vocation is usually discerned after being involved in Opus Dei's activities (retreats, classes, spiritual direction) regularly over a period of time, which enables one to acquire an in-depth knowledge of Opus Dei. It is also important to acquire consistency in the Christian practices to which members commit themselves: frequent reception of the sacraments, prayer, apostolate and, in general, a humble and constant effort to acquire virtue and struggle for holiness in keeping with the spirit of Opus Dei.
Adult Catholics, men or women, married or single, of any background, nationality or socio-economic condition, may be incorporated in the Prelature.