As a mainline Protestant, I guess the question itself shows one of the biggest hurdles Christian reconciliation has yet to overcome - our collective insistence that everything is defined in terms of right or wrong. Essentially this means if my faith tradition is correct, then by definition yours must be wrong.
To me this almost implies a God with very limited power, as He or She can only support a single, very specific path to salvation.
I reject this notion and ask, “Who says the Catholic tradition is wrong?”
Mainline Protestants, the denominations who trace a direct lineal heritage back to the magisterial reformers Luther, Zwingli and Calvin, seem to have evolved into a theology that is much more inclusive in such matters. There seems to be recognition that scripture is absolutely clear and specific on many of the important, core, fundamental foundations of the Christian faith. These are boundaries that cannot be crossed.
In some of the details, however, scripture comes across as vague, ambiguous and often contradictory, thus leaving it to sincere, divinely inspired, yet mortal men (whether they be named Luther or Benedict), to decipher the ultimate truth of an infinite, all powerful and all knowing God. Is it possible, or might we get closer to the ultimate truth by learning from each other and the reasons behind the various traditions. Indeed, could all have some element of truth because an all powerful God cannot be limited, for example, to a single type of real presence at communion?
Mainliners tend to recognize this possibility and thus consider their faith traditions somewhat similar to the first among equals, not the only correct way to God. Other Christian traditions are considered equally valid paths, ones to be both respected and learned from. At the very least, as my pastor says, “doubt the interpretation perhaps, but not the faith behind it.”
Its why we recently had a sermon on Mary, noting that perhaps the RCC is a bit closer to giving her the credit she deserves and that perhaps we Presbyterians should reconsider our own thoughts about the Virgin.
Finally remember that just as there Sedevacantists and Conclavists under the Catholic umbrella, Protestant traditions cannot be lumped into a single definition. And perhaps this is a good thing. If indeed research and dialogue is the most effective path to understanding God’s truth, could it be that the Reformation itself was divinely inspired?
JMTSW, YMMV