This is not true,if anything it's many protestant communities who preach people are cursed to hell.
To set the record straight ,dear Sister,here is what the Church says regarding protestants
From Dominus Iesus...
"those who are baptized in these communities are, by Baptism, incorporated in Christ and thus are in a certain communion, albeit imperfect, with the Church....these separated Churches and communities as such, though we believe they suffer from defects, have by no means been 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 Catholic Church”
Some people, finding what we actually teach a more difficult target, prefer to attack what we do not teach. They will not hear our teaching.