The person answering the questions at EWTN seems to indicate that any change in the form invalidate the confession:
However, I haven’t found anything official clearly supporting this. It seems reasonable though that if the priest follows the essential elements to the formula the absolution would be valid (CCC #1449):
However, while changing the formula of absolution may be valid it would still most likely be illicit. The problems with using an illicit formula could be twofold:
- The formula might not be valid.
- Even if it is valid changing the formula could put the validity of the Sacrament in doubt and the penitent could be robbed of a sense of peace that he or she might normally receive when hearing an absolution that they know is valid.
Also, a scrupulous person might fear they are sinning by not correcting the priest if they hear the priest chaning the formula but at the same time be afraid about confronting him.
Imagine if the next time you went to confession you heard this formula of absolution (CCC #1481) instead of the normal:
Now, since it is a formula recognized by the Byzantine Liturgy it seems reasonable to me that it would be valid regardless of the Rite. However, it seems to me that using the formula in the Latin Rite (even though it is invalid) would be illicit since the parishoners are not accustomed to the formula and may doubt the validity of the Sacrament.
I am interested in some official Church documents that I could use that show that it’s wrong to change the formula of absolution. Without them, it might be hard for a lay person like myself to convince a priest to stop changing the words of absolution.