(3) The dogma must be understood and explained as the Church’s magisterium understands and explains it.
Hence, too,that meaning of the sacred dogmas is ever to be maintained which has once been declared by holy mother church, and there must never be any abandonment of this sense under the pretext or in the name of a more profound understanding. - First Vatican Council
(5) Because the Church is necessary for salvation with the necessity of precept, any person who knows the Church to have been divinely instituted by Our Lord and yet refuses to enter it or to remain within it cannot attain eternal salvation.
But the worst thing of all is religious proselytism, which paralyzes: “I am talking with you in order to persuade you.” No. Each person dialogues, starting with his and her own identity. The church grows by attraction, not proselytizing. - Pope Francis
(7) In order that a man may be saved “within” the Church, it is not always necessary that he belong to the Church in re, actually as a member, but it can sometimes be enough that he belong to it as one who desires or wills to be in it. In other words, it is possible for one who belongs to the Church only in desire or in voto to be saved.
(8) It is possible for this desire of entering the Church to be effective, not only when it is explicit, but also (when the person is invincibly ignorant of the true Church) even when that desire or votum is merely implicit.
It firmly believes, professes, and proclaims that those not living within the Catholic Church, not only pagans, but also Jews and heretics and schismatics cannot become participants in eternal life, but will depart “into everlasting fire which was prepared for the devil and his angels”, unless before the end of life the same have been added to the flock; and that the unity of the ecclesiastical body is so strong that only to those remaining in it are the sacraments of the Church of benefit for salvation, and do fastings, almsgiving, and other functions of piety and exercises of Christian service produce eternal reward, and that no one, whatever almsgiving he has practiced, even if he has shed blood for the name of Christ, can be saved, unless he has remained in the bosom and unity of the Catholic Church. - Pope Eugene IV Cantate Domino
(9) The Mystici Corporis reproved both the error of those who teach the impossibility of salvation for those who have only an implicit desire of entering the Church, and the false doctrine of those who claim that men may find salvation equally in every religion.
In Mystici Corporis, the Pontiff lucidly distinguishes between those who are incorporated in the Church as members, and those who cleave to the Church by a kind of wish. ". . . Actually only those who are to be included as members of the Church who have been baptized and profess the true faith
, and who have not been so unfortunate as to separate themselves from the unity of the Body, or been excluded by legitimate authority for grave faults committed." - Pope Pius XII Mystici corporis Christi