Ex opere operato is a Latin phrase meaning "from the work worked" that, in reference to sacraments, signifies that they derive their efficacy not from the minister (which would mean that they derive it , meaning "from the work of the worker"), nor from the recipient, but—independently of the merits of either—from the sacrament itself. According to the interpretation of the sacraments, any positive effect comes not from any human worthiness or faith, but from the sacrament as an instrument of God.
In the words of Dominican priest Jorge Scampini, S.T.M., "Affirming the efficacy means being sure of God's sovereign and gratuitous intervention in the sacraments." For example, in confirmation the Holy Spirit is bestowed neither through the attitude of the bishop nor that of the person being confirmed, but freely, by God, through the instrumentality of the sacrament. However, in order to receive sacraments fruitfully, it is believed necessary for the recipient to have faith.
Antiquity
In Antiquity, the idea led to a schism among the Donatist Christians.
Origin of the expression
The expression opus operatum is first found in the writings of Peter of Poitiers (1125–1205).
In the Roman Catholic Church
According to the teaching of the Roman Catholic Church, to receive the fruits of the sacraments requires that a person be properly disposed. This means the efficacy of grace via the sacraments is not automatic. There must be, at least in the case of an adult, an openness to use the sufficient grace which is available in a sacrament. When the recipient is properly disposed, "the sacraments are instrumental causes of grace."
Biblical basis of the sacraments
The sacraments work ex opere operato as manifestations of Jesus' actions and words during his life. Baptism and Confirmation are the manifestation of Jesus' baptism by John the Baptist and anointing by the Holy Spirit, Holy Orders is the manifestation of Jesus' calling of the twelve Apostles, Matrimony is the manifestation of the Wedding at Cana, Anointing of the Sick is the manifestation of Jesus' miracles, Confession is the manifestation of Jesus' forgiveness of sins, and the Eucharist is the manifestation of the Last Supper and Paschal Mystery.
Sacramentals
The teaching of the Roman Catholic Church regarding sacramentals is their efficacy comes ex opere operantis Ecclesiae (i.e., from what the doer, the Church, does), not ex opere operato (from what is done): i.e., as the Second Vatican Council said, “they signify effects, particularly of a spiritual kind, which are obtained through the Church's intercession”. They “do not confer the grace of the Holy Spirit in the way that the sacraments do, but by the Church's prayer they prepare us to receive grace and dispose us to cooperate with it”. Sacramentals dispose the soul to receive grace and may remit venial sins when used prayerfully.
In the Lutheran Churches
thumb|right|Lutheran priest elevating the host during the [[Mass (liturgy)|Mass at Alsike Church, Sweden]]
The Lutheran Churches see as sacraments: baptism, the eucharist, as well as confession and absolution.