Baptism of Desire is Catholic Doctrine. The necessity of the Catholic Faith for Salvation is also a certain Doctrine. Pope St. Pius X, following St. Alphonsus and the other Doctors, defines the doctrine of Baptism of Desire as an act of Perfect Love of God, or of Contrition, along with the Desire, explicit or implicit, of the Sacrament of Baptism. In another place, the same Holy Father teaches that all who are saved had embraced the Catholic Faith (which means explicitly at least the Holy Trinity and Incarnation) before death. It follows that all who receive the Baptism of Desire will be led by God to embrace the Catholic Faith, at least at the point of death. This is also taught by Fr. Michael Mueller in a 19th Century Catechism approved by Rome. There is a minority view which is permitted by the Magisterium of the Church that faith that God Exists and that He rewards is sufficient for salvation; but the Doctors commonly teach that explicit faith in Christ is a necessary means of salvation. This was the state of the question before Vatican II and it still is today.