I think that in the area of the doctrine of salvation, that Roman Catholic doctrine as I understand it is unbiblical. It is equivalent to the Galatian heresy, which is that faith plus works makes salvation. I know that not all Catholics would agree that that is a fair way of putting it, but I think that most Catholics would actually put it that way. Your faith and your works are what save you. Now, I need to add this too.
Many Protestants feel the same way.
Many Protestants are confused on this issue so this is not a Catholic versus Protestant concern so much. It's just that Catholicism across the board has more of an official position that states this, where Protestants have all different kinds of views and some of them don't seem to be consistent with Protestantism. But the fact that one believes that Jesus is the Messiah and that He is the Savior is very, very critical. If you reject this notion, like the Jews do, then as far as I can tell from the biblical revelation, there is no hope for you. That seems to be eminently clear.