If they have that authority and they do teach scripture then why is it so difficult for catholics to use scripture to support what they believe? What I see is allot of other literature and many opinions of authors...but very few catholics use scriptures to support their opinions and beliefs....it's more what the catholic leadership tells them, or what comes out of Rome they have to believe...and that is bondage not freedom in Christ.
BTW the catholic church is indeed another denomination...is it not the "catholic" faith?
Why is it difficult? Not at all. The scripture is filled with Catholic doctrine everywhere you look. There are things not in the scripture, and for their propaganda purposes the anti-Catholics want to talk about that, but if you stick to the things that the Scripture contains, it is all Catholic.