I thought I'd split the answer to this one out here as it's a total diversion. With respect, you really are clutching at straws here. You didn't bother providing a link to support your quotes but it's easily findable. Your extract is from [broken link removed], an American fundamentalist pastor of the evangelical Baptist tradition. It's reproduced on several fundamentalist, mainly Baptist websites. I'm going to guess you don't know a whole lot about evangelical fundamentalism. It has more and less moderate strains, but this is very much the less moderate variety -- the same one from which Ian Paisley Snr took most of his inspiration. Whereas Catholics and some Evangelicals have arrived at joint declarations about the nature of salvation "by grace through faith", the truly diehard evangelicals still cling rigidly to the "solae" of the Reformation.
One can imagine the very title of the encyclical
Fides et Ratio (Faith and Reason) being a bit of a red rag to a bull for a
sola fide fundamentalist ("salvation through faith alone"). But the specific complaint in your article is that in that encyclical the Pope cites Tradition in talking about the Eucharist, instead of "
sola scriptura" ... only scripture. Never mind that the encyclical is extensively footnoted, like all encyclicals, to demonstrate continuity of doctrine with previous sources. Costella's complaint is that the RCC
hasn't changed its theology which is why evangelicals should stay away from it, exactly the opposite of what you claim. This is hardly even worth debating (although we can if you insist) -- but you should find some sources other than the crazed regressive fundamentalist Catholic-hating ones still occupying the battlefields of the Reformation. Or at least be a
little bit more discerning when you google "has the church changed its doctrines".