Actually, your probably a very smart guy. It is a spurious argument. However, have you ever compared and contrasted your beliefs and the bible verses that support them versus what Catholicism teaches and the bible verses they use to support it. So many people verify truth initially with their religion and then just use that support beam for truth on all the rest without checking. So they know that all the other denominations got it wrong because their literature and experts tell them about all the other denominations.
Borrowed Opinion. Usually when I contradict something in another denomination(like Mormonism), these guys just usually go back to an elder and get there take. Its kind of a waste of time. Because these people rely on borrowed opinions instead of search for truth. Why do all these contradictions in faith exist...not enough fact checkers, too many people with emotional investments. Keep on the search my friend. I’ve been there , done that.
Thank You and God Bless.