One would not, but you are avoiding the question. Where in it does it say it is God’s Word, and that it must be believed in order for someone to be saved?
And along those lines, do you believe that no one was saved before it was written?
Have you ever considered that you are the one who might be confused?
Most of Paul’s letters were written before the four “memoirs of the Apostles” that we know of as the four Gospels. When Paul referenced the Gospel, he was talking about what was preserved in Catholic Sacred Tradition - the kerygma, or the preached Word of God.
No. Catholics find the Holy Scriptures profitable in learning how to be in right relationship with God. It was never intended to be a comprehensive “guide” or “manual” of the Christian life. This is the role of the Church, founded by Christ. The Bible is a product of the Church.
No, this was established by the Apostles under the guidance of the HS. The NT reflects the shape of the Church, but is not the source of it. Jesus is the Source.
That is why, when the NT is taken out of it’s context (the Catholic Church) the meaning of the text is lost. The Church did not come from the Bible, but the Bible from the Church. It cannot be properly understood unless one reads it from the perspective of those who wrote it, which is Catholic.
When the Scriptures are read through the lens of the Catholic Sacred Tradition that produced them, of course. When the writings are separated from the faith that produced them, the meaning is lost, and the reader wanders away into various heresies and misunderstandings.
You are still dodging the question, schaick. How do you know that the books you call “the Bible” are really God’s Word? Most of the books don’t claim this for themselves.
You are not Catholic because you did not realize that the Bible is a Catholic book?

I am sorry, I am confused. You seem like someone who values the Bible a great deal. It seems that you would also value the Church that produced it.
The Scriptures are sufficient to lead one to Christ, and therefore, to His One Body, the Church, through which He has provided all those things necessary for our salvation.
My beloved brother. Your error in this matter will be cleared up with just a little scripture study. When you study the history of your faith, it will become clear that Paul wrote as many a two decades before the Gospels were written. Paul, like all the early Christians, learned the gospel through Catholic Sacred Tradition, by which the NT was produced.
The scriptures referenced here are the Septuagint, the Alexandrian Old Testament, which was used by Paul. He learned the Gospel from the Apostolic kerygma, and personal divine revelation. He did not read it from Matt. Mk. Lk. or John.
This reference is also from the Septuagint.