“As a Protestant, I have been told by a few Roman Catholic on this forum, I am damned to hell because I don’t belong to the one true Roman Catholic Church...”
“It follows that these separated churches and Communities, though we believe they suffer from defects, are deprived neither of significance nor importance in the mystery of salvation. In fact the Spirit of Christ has not refrained from using them as instruments of salvation, whose value derives from that fullness of grace and of truth which has been entrusted to the Catholic Church”— Pope B16, Dominus Iesus
Next time tell them to take it up with the Popes.
Freegards
It follows that the separated Churches and Communities as such, though we believe them to be deficient in some respects, have been by no means deprived of significance and importance in the mystery of salvation. For the Spirit of Christ has not refrained from using them as means of salvation which derive their efficacy from the very fullness of grace and truth entrusted to the Church.- Unitatis Redintegratio, Vatican II
Prior to Vatican II the Catholic Church did not teach this.