and these people learned of Christ, other than through the Catholic Church......how??? there was no other source of Christian knowledge and teaching than the Catholic church...
Actually there was a great deal of information and sources of Christian knowledge before the Church hunted them all down and slaughtered them.
But then, after it killed averyone, it declared them to be heretics and their beliefs to be non-Christian.
So - shazam - there weren't any Christians other than the Church after all.
See? All cleared up.