Well, that's an interesting response! Now that you've made it clear you
believe I'm wrong, care to show me
how I'm wrong?
I have a pretty good knowledge of Christian history, though this isn't really a historical debate; It's more of a theological/philosophical one.
Regardless, here are some quotes from the Catholic Catechism, so you can correct yourself and understand that what I've said thus far is consistent with Catholic belief:
For the truths that concern the relations between God and man wholly transcend the visible order of things, and, if they are translated into human action and influence it, they call for self-surrender and abnegation. The human mind, in its turn, is hampered in the attaining of such truths, not only by the impact of the senses and the imagination, but also by disordered appetites which are the consequences of original sin. So it happens that men in such matters easily persuade themselves that what they would not like to be true is false or at least doubtful (CCC 37)
...Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it. (CCC 846)
this affirmation is not aimed at those who, through no fault of their own, do not know Christ and his Church: Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience—those too may achieve eternal salvation. (CCC 847)
As you can see, in
CCC 37, The Catholic Catechism teaches that humans can easily persuade themselves that there is nothing past the physical, scientific world, and thus believe there is no God.
In
CCC 846-847, the Catechism goes on to say that those who are ignorant of the faith and God, but still follow God's will by listening to their conscience and living good lives, may also have eternal life.
Hence me saying that non Catholics of all kinds can possibly achieve eternal life depending on their individual circumstances and character.
If you doubt this, go online or to a local parish and ask a priest
(Heck, just from a quick google, I've already seen an "ask a priest" style search result, where a priest of the Franciscan order answers the question in agreement with me

)
Meanwhile, the majority Protestant denominations believe in "faith only" salvation, which is exactly what it says; one
must have faith in Jesus Christ as their personal savior to have eternal life. No exceptions ("faith only" also means "only those with faith will be saved"

)
Don't believe me? Ask a Southern Baptist or a Pentecostal, or some denominations of Presbyterians and Lutherans (All four of those groups rank as the
largest Protestant denominations out there, after Anglicans and Methodists [which, it's worth noting that some Anglican and Methodist denominations agree with "faith alone"]).
Of course, not all Protestant denominations hold that limited view of God's mercy.
Regardless, I hope this shows you that it is, in fact,
you who is confused here.
No offense, but your surface-level reading of what "Protestants believe" and "Catholics believe" truly is inaccurate.
I question how much research you actually did before making your claims... Not that I hold your misunderstandings on the subject against you.
You are a secular humanist, after all, and this stuff isn't exactly common knowledge for people outside of the faith (though you may have at one time been a Catholic, I don't know; if you were, it appears you weren't properly catechized).
EDIT: Also, sorry for writing a novel here

didn't realize how long it was. When I'm right about something, I get carried away (ENTP, here). Plus, this is a subject I love discussing.