The majority of Christians in the USA think that the Bible is the complete and inerrant word of God, as written by divinely inspired humans. Just Google up the mission statement for a local mega-church and I'll bet 50DKP it says something to that effect on their About Us page.
Many, many self-proclaimed Christians in the United States have, at best, cursory Biblical knowledge. Insofar as reading, they may have opened the book in their lives. That does NOT equate to critical analysis, or even perfunctory understanding the contents in even a general sense.
The gospels were not written by the people with their names on them. Part of the problem of just reading the Bible is that it's incredibly inaccurate. It's authorship is up to a lot of debate.
I'm just saying that if someone claims the Bible has been written by God Himself then they must not have even looked inside, because the Bible itself assigns clear authorship to each book. I'm not talking about historical accuracy here.
Edit: in my country when I was growing up, the common perspective was simple: there are two main religions - Christian Orthodox and Catholic. All other Christian denominations were "sectarians". Non-Christian religions were not even considered, those were "pagans".
I was born in Tatarstan. For us, the division was Christian or Muslim. "Christian" was assumed to be Orthodox, but Catholics were considered to just be a kinda weird foreign flavour of Christianity. Pretty much everyone else made their presence known by proselytizing, and thus earned the title of sectarian for being a crazy evangelist (a chill immigrant who happens to be a Buddhist or Anglican doesn't really talk much about their religion, so thus the only small religions you notice are the ones headed by people who don't mind their own business).