There is an argument out there that since the mass is a representation of the cross of Christ and, as the Roman Catechism puts it, "is truly a propitiatory Sacrifice, by which God is appeased and rendered propitious to us", we have no need of confession. Further from the Roman Catechism on this point:
There are also several popes who've said the same thing. I've been having difficulty coming up with a response to the statement that because of this Confession is superfluous. Can you speak to this?
- "If, therefore, with a pure heart, a lively faith, and affected with an inward sorrow for our transgressions, we immolate and offer this most holy victim, we shall, without doubt, obtain mercy from the Lord, and grace in time of need; for SO delighted is the Lord with the door of this victim that, bestowing on us the gift of grace and repentance, He pardons our sins. Hence this usual prayer of the Church: As often as the commemoration of this victim is celebrated, so often is the work of our salvation being done; that is to say, through this unbloody Sacrifice flow to us the most plenteous fruits of that bloody victim."
Well, first of all, we find the passage you quoted in the section of the Roman Catechism on the Sacrament of the Eucharist, under the subheading "The Mass: A Sacrifice of Praise, Thanksgiving and Propitiation." I suggest reading the entire section.
Now, when it speaks here of sins being pardoned through the offering of the Sacrifice of the Mass, it is important to note that the sins in question are venial, not mortal. Farther up, under the subheading, "The Eucharist Remits Venial Sins," we read, "It cannot be doubted that by the Eucharist are remitted and pardoned lighter sins, commonly called venial."
We know that the Roman Catechism is not asserting that mortal sins are remitted by the Mass because, farther down, in the third paragraph under "Preparation of Soul," it states:
- We should, in the next place, carefully examine whether our consciences be defiled by mortal sin, which has to be repented of, in order that it may be blotted out before Communion by the remedy of contrition and confession. The Council of Trent has defined that no one conscious of mortal sin and having an opportunity of going to confession, however contrite he may deem himself, is to approach the Holy Eucharist until he has been purified by sacramental confession.
I hope that helps.