Are unconfessed mortal sins forgiven during confession?

I know that if you INTENTIONALLY do not confess a mortal sin, you commit an invalid confession. However, what about if you honestly forget? Specifically my question is: [list=1]*] Is it true that mortal sins need to be confessed in order to be forgiven or would something like: " … for these and for all my sins as they stand in the eyes of God, I ask for penance and absolution … " cover any forgotten mortal sins?

*] If a mortal sin is later remembered, does it have to be confessed or was it already forgiven by the " … for these and for all my sins as they stand in the eyes of God, I ask for penance and absolution … " of the earlier confession?

*] If the answer to the above question is that the sin needs to be confessed, then does that mean that any communions received were therefore received unworthily and therefore, those are mortal sins as well and also need to be confessed?[/list] I realize that this may all sound too ‘technical’ but I recently was away on a retreat and instead of enjoying my quite time with the Lord, I spent a majority of my time trying to track down priests to keep confessing … first to confess the original mortal sin; then, realizing after confession that I had received with that mortal sin, I now had another mortal sin which also need to be confessed / forgiven in order to wipe the slate clean.

Dear Sir K,

Usually, it is best to conclude our confession by saying, “I’m sorry for these and any sins I may have forgotten” or “all the sins of my past life”. But even if we don’t say this, any mortal sin that we have forgotten IS forgiven when the priest absolves us. However, if we should later remember a mortal sin from the past that we have not explicitly mentioned—even though it HAS been forgiven, we OWE God the acknowledgement of it to the priest, the next time we go to confession. Our Lord endured such agony to redeem us. The least—the very least we can do, is to acknowledge it to Him in the person of His priest! It’s an act of humility and gratitude and the Lord deserves to hear it.

Fr. Vincent Serpa, O.P.

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit