Let's see what everyone thinks of this scenario:
God creates a soul in a baby boy in Asia, whose parents are not Catholic. Because of this, he never receives baptism with water. As he passes the age of reason and approaches age 9, he is very pious, strictly obeys the natural law, and has perfect contrition for all the sins of his short life so far. His primary disadvantage at this point is that he is in invincible ignorance of the Catholic faith, simply trusting and obeying his parents as God would expect him to up to this point.
Now if this young boy of age 9 is suddenly killed in an accident, not yet having had the chance to even begin exploring where the true Church lies, do you truly believe that an ALL JUST God would damn this boy for all eternity to the fires of hell, when it is God Himself who placed this boy in this non-Catholic family, not even giving this boy the slightest chance of finding out about Catholicism? If you say yes, then you are saying that God is not just - that He unjustly damns souls through no fault of their own.
Pope Pius IX plainly shows this boy would likely be saved through implicit baptism. This interpretation is the only interpretation that makes sense given that God is all just:
Quanto Conficiamur Moerore, 1863: “There are, of course, those who are struggling with invincible ignorance about our most holy religion. Sincerely observing the natural law and its precepts inscribed by God on all hearts and ready to obey God, they live honest lives and are able to attain eternal life by the efficacious virtue of divine light and grace. Because God knows, searches and clearly understands the minds, hearts, thoughts, and nature of all, his supreme kindness and clemency do not permit anyone at all who is not guilty of deliberate sin to suffer eternal punishments.”