“Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience–those too many achieve eternal salvation.” - Lumen Gentium
For those who reject the Catholic faith because of incomplete knowledge or circumstances beyond their control that kept them from discovering the fullness of truth that exists in the Church, we hope and pray that they also will be saved.
“First of all, then, I ask that supplications, prayers, petitions, and thanksgivings be offered for everyone, for kings and for all in authority, that we may lead a quiet and tranquil life in all devotion and dignity. This is good and pleasing to God our savior, who wills everyone to be saved and to come to knowledge of the truth.” - 1 Timothy 2:1-4 NAB