From an article on CA; hope this is helpful:
*Necessary for Salvation
As we have seen, God introduced salvation to the world through his chosen people, the Jews. God’s revelation to the Jews found its fulfillment in Christ, the Messiah, who established the Catholic Church. The grace necessary for salvation continues to come from Christ, through his Church. Those who innocently do not know and embrace this might still attain salvation but those who knowingly and willingly choose to reject it, reject salvation on God’s terms.
The Catechism (once again quoting Lumen Gentium) summarizes all this as follows:
Basing itself on Scripture and Tradition, the Council teaches that the Church, a pilgrim now on earth, is necessary for salvation: the one Christ is the mediator and the way of salvation; he is present to us in his body which is the Church. He himself explicitly asserted the necessity of faith and baptism, and thereby affirmed at the same time the necessity of the Church which men enter through baptism as through a door. Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it. (CCC 846)*
Jim Blackburn is a Catholic Apologist, Author, and Speaker. He holds a Masters Degree in Theology from John Paul the Great Catholic University and is the author of several books including 101 Quick Questions With Catholic Answers: Marriage, Divorce, and Annulment, 20 Answers:…