Problem with the above scenario is that the priest is wrong. But
I suppose the above is just a caricature to take a jab at
Christianity or Roman Catholicism.
Anyway, a Christian who knows the Bible well enough will know
that the Bible is not silent on this. In the book of Romans the
Apostle Paul said that people DO KNOW about God and sin. He said
that the evidence for God is seen in the creation and thus people
are without excuse. It is not that people do not know, but that
people suppress the knowledge of God. As to sin, if you ask
everyone, they can tell you that they are not morally perfect. We
all know in our hearts that we have done wrong. We have lied, we
have stolen, we have coveted etc etc. God has given us His law
aka the conscience which functions as a moral compass albeit marred
by sin such that people can have their conscience hardened or
seared by repeated wrongdoing. Even if we do not know or heard of
the 10 commandments, our conscience can still judge us.
Christians around me told me that babies who passed away without
the knowledge of God will not go to hell and people who did not
have the chance to know God will not go to hell. How come there are
differences in understanding among Christians?