In my research and writing on Pentecostal sacramentality I have come to appreciate the tension between ex opere operate and ex opere operantis. Please bear with me. The classic Catholic understanding of sacraments is that they convey God’s grace ex opere operate, that is, by virtue of the act. The faith of the recipient is not required. As long as the sacrament is properly administered and grace is not resisted, grace is conveyed. The classic Protestant understanding of sacraments is ex opere operantis, that is, by virtue of the work. Grace is conveyed because of the faith of the recipient and/or the celebrant.
There is an irony here. The Catholic view of ex opere operate insist that the conveyance of grace through the sacrament is an act of unmerited grace. The Protestant view of ex opere operantis suggest that the conveyed grace of the sacrament is merited by the act of faith. In the Catholic view the sacrament is salvific because of the faithfulness of Christ. In the Protestant view the sacrament is salvific because of the believer’s faith. The Catholic view of grace and the Protestant view of merit often escape serious consideration.
(sursa Daniel Tomberlin)