To start off with when one is in the state of mortal sin he is NOT IN FULL COMMUNION with the Church or with God. That is the Sacraments purpose is to primarily reconcile us to God and secondarily reconcile us to the Church.
If we start to say that Christ only forgives those that are Catholics we go down a very bumpy road. Also if a Non-Catholic Christian comes before a priest to confess his sins, he is in fact by his very actions recognizing the authority of the Church and the power bestowed on the Priest.
Also it should be pointed out that Eastern Othodox Christians can receive the Sacraments from a Catholic church if there is no Othodox church available to him or her. So the full communion does not stick.
ERose, I never said that Christ only forgives those who are Catholic. What I said is that the sacrament is reserved for Catholics becasue they are full members of the Body of Christ in union with Peter’s successors. In order to be Catholic, you must profess what the Church believes, that includes the fact that Christ charged his apostles and their successors with the authority to forgive sins. The apostles’ successors, the bishops, in turn, hand that authority to the priests.
You did bring a valid point regarding the Orthodox. While “perfect” commuion does not exist between the two sister Churches, our Church recognizes that there is apostolic succession with the Orthodox. We are allowed to receive Holy Communion in their churches if we are unable to reach one of our own (due to travel in a country where there is no Catholic church available). Remember, when Pope Benedict XVI visited the Greek Patriarch in Turkey, he was present at their liturgy, but did not concelebrate. The reverse was true when the Greek Patriarch was in attendance at the Papal Mass. He was there, but, he did not “concelebrate” with the Holy Father. In essence, neither the Holy Father nor the Patriarch concelebrated each other’s rites because perfect communion does not yet exist.
The Church does not recognize the Protestant ecclesial communitise as “churches.” That is why the Congregation of the Doctrine of the Faith issued a document in 2007 defining that relationship. The Protestants do not have apostolic succession; therefore, they do not have the full compliment of our sacraments. The also do not recognize the authority of Peter and the Magesterium.
One could argue that there is some reasonable apostolic succession in the Anglican communion. However, somewhere down the 500-year schism, that line was broken. Certainly the women the Anglicans ordained do not follow under the apostolic succession. But, that is for another thread to tackle.
Your earlier point about Baptism is somewhat erroneous. We become Catholics when we are baptized into the Church. We complete the initiation when we have received first Holy Communion and Confirmation. Confession is part of the package because in order to receive Holy Communion the first time around, we need to become reconciled with God, through Communion.
Although someone commits mortal sin (i.e. living in an invalid marriage, etc), that still does not remove the obligation to attend Mass. There is also room for conversion. You don’t have to receive Holy Communion at Mass in order to fulfill your Sunday obligation. My beloved Grandmother lived in an invalid marriage for many years (until her annulment) and she never stopped going to Mass. In fact, she was the one who introduced me to Triduum. When her annulment finally came through, she was happy to finally be able to receive the Sacraments.