thistle:
That is not actually correct. The Church teaches that if you die in a state of mortal sin you go to Hell for eternity, not that you might or could.
Sorry, but it is correct [that hell might be empty]. The Church has always maintained that it is impossible to know if we are actually in a State of Grace (and thus we cannot know if we are in a state of mortal sin). When the English inquisitors asked St. Joan of Arc if she was in a State of Grace (a trick question, they thought), she wisely replied, “If I am in this state, I ask that God keep me there; if I am not in this state, I ask that God place me there.”
People have said things like, “surely Hitler (Stalin, etc) is burning in hell,” to which the wise Chrisian correctly responds, “we don’t actually know that for sure - we have no way to know what Grace these wicked persons may have obtained, even at the moment of their last breath, owing to the infinite Mercy of God.”
So the Church doesn’t actually teach that ANYONE is presently in a state of Grace, and/or of mortal sin. The Church says we simply cannot be sure (we can be pretty sure, but not absolutely certain).
If we cannot be 100% sure that anybody is in a state of mortal sin, we can’t be 100% sure anyone dies that way. So we can’t be 100% sure that there is anyone who is actually in hell.
The Church teaches that it is possible to go to hell. But the Church absolutely does not teach in any way, shape, or form that anyone actually DOES go to hell, or that hell is not empty.
Oh, FWIW, I think hell is quite crowded. But that’s my opinion. It is NOT Church doctrine.