As far as I know, a mass said by a priest who has lost friendship with God (in the state of mortal sin) is valid by the principle of ex opere operato, justified by the resolution of the Donatist controversy deciding on the side of the sacraments performed are still efficacious. If my understanding is correct, it's Christ himself who is the author of the sacrament, who in principle can make the matter and the form of the sacrament (the Sacramentum Tantum) STILL be the causal instrument of grace to the recipient, making the sacraments efficacious.
But if generally, a mortal sin causes the loss of not only the sacramental effects (Res Tantum) but also the sacramental character (Res et Sacramentum), doesn't this mean that the mortal sin also has an effect on Holy Orders?
My question is: How does Catholic Sacramental theology explain the efficacy of sacraments performed by a priest in the state of mortal sin?
Maybe I was wrong to say that the mortal sin affects the sacramental character. Maybe the sacramental character is never removed. One explanation is that mortal sin introduces an obstacle (obex). But this introduces other questions:
- If the sacramental character is never removed but there is an obex, what exactly is blocked within the priest if the Eucharist / Baptism offered / performed are still to be efficacious?
- Similarly, if the sacramental character is never removed, does it mean that when we commit mortal sin, the life of the Holy Spirit given at Baptism never leaves us, but only the effects (virtues, gifts, actual grace, etc.) cannot flow to us? How do we reconcile the seemingly incongruent idea that the life of the Holy Spirit can coexist with the state of mortal sin?
For a background explanation of the Catholic tri-partite theory of sacrament, see attachment to a related question.