If Bible is not "final authority", does it mean it is not true and we can reject it entirely?
If the Bible is a Catholic book, why do they go against it?
Every body, every denomination does things Scripture says not to do.
Jesus said , "unless you eat the flesh and drink the blood of the son of man, you have no life in you"
At every last supper account he said "this is my body, this is my blood". He lost followers over that teaching.
Paul said if you eat and drink communion , without discerning the body and blood of our Lord, you eat and drink condemnation upon yourself.
He said people have gotten sick and died from receiving holy communion unworthily. If it was just symbolic, and not the body and blood of our Lord, why does it say otherwise, and why were people dying, who received it unworthily??
Most denominations of Protestantism reject those very important verses about the sacraments.
Jesus also gave the Apostles the ability to forgive sins, like Catholic priests do.
God said "thou shall not murder, thou shall not make a graven image" , then later commands murder of babies, pregnant women, children, and civilians (genocide), and making a brazen graven Serpent that Israelites must turn to for healing, golden Angels at the ark, and graven images, all commanded by God, against the ten commandments!
God often commands in Scripture, that people do the opposite of what other Scriptures say.
The Bible is an extremely confusing book.
That is why Jesus left earth with a Church, not a Bible.
Plus, I don't know of a single denomination that doesn't go against some Scriptures. God himself has commanded people to do the opposite of what Scripture says, in the Scriptures, and God changes his mind at times too, in the Scriptures.
Hence the need for a Church!