Ex opere operato is a Latin theological expression meaning "by the work worked." It refers to the fact that the sacraments really work—they confer grace when the sacramental sign is validly effected, not as the result of activity on the part of the recipient, but by the power and promise of God.

To receive the fruits of the sacraments requires one to be properly disposed. This means reception of grace via the sacraments is not automatic. There must be, at least in the case of an adult, a predispositional receptivity to receive the grace which is always available in a validly effected sacrament.

The ex opere operato nature of the sacraments affirms that while a proper disposition is a necessary precondition to receiving grace in the sacraments, it is not the cause of that grace. What God offers in the sacraments is a free gift. Not even a person's own dispositions, as good as they may be, produce God's supernatural life in that person.

External link

• http://mb-soft.com/believe/txn/exopere.htm