Thank you for your in depth input, much appreciated. Yes, in fact, I did learn from a Catholic person --- are you saying that because people applied the hermeneutic method to "understand" the bible is what resulted so many denominations - how could that happen? I thought Catholic was a Christian denomination? When was the beginning of documented Christian beliefs/bible? Besides Christian religions, are there non-Christians religious folks who believes in angels and how do they define them? Since I'm not that well educated in religious stuff, what's the difference between Judaism and Christianity?

@DeafGypsy Christianity began as a Jewish sect. To over-simplify the situation, the Jewish religion said there would be a Messiah or chosen one who would lead Israel out of bondage to the Romans and the earliest Christians identified Jesus as that Messiah. The Jewish establishment rejected this. That's the super over-simplified version. Of course Jesus didn't end Roman dominance; indeed, the Romans stepped it up a few decades after the alleged crucifixion and sacked Jerusalem and destroyed the Temple. So the "kingdom" Jesus spoke of became spiritual and metaphorical and personal rather than national or political. Somewhere in there, Judaism decided to no longer tolerate the Christian sect (known as "the Way" ) and the sect eventually found their following among the Gentiles.

The first collected works of the New Testament (a version of the gospels and the writings of Paul) were, ironically, collected by the heretic Marcion somewhere in the early 2nd century. The New Testament more or less as we know it today was finalized around AD 325 (early 4th century). The scholarly consensus is that it was all authored between AD 47 and AD 90, give or take, but there are contrarians who contend that those datings are way too early. We have few manuscript fragments older than the 4th century, and the ones that exist are tiny fragments dating from the 2nd century. Dates of authorship are inferred indirectly from textual evidence. No one has, or even claims to have, the original manuscripts. We have copies of copies of copies. Our modern English translations are based on the best surviving manuscripts available to us.

There are more than four gospels. There are just four that made the official cut. There are a number of books, collectively known as the apocrypha, that were rejected candidates for inclusion in both the old and new testaments. The Roman Catholic and Eastern Orthodox church accepted a handful of these and include them in their versions of the Bible. The protestants do not. And there are still other books that survive in whole or in part, that aren't included in anyone's Bible. The decisions on those matters were taken up by early church councils.

I am personally pretty rusty about angels but I know that Judaism and Islam both had them and most of the named angels (e.g., Michael, Gabriel) are held in common between those three Abrahamic faiths. Mormonism has angels in the Book of Mormon and other Mormon holy books that they use in addition to the Bible -- one of their major angels is named Moroni. Other religions have various demigods and supernatural actors similar to angels.

Yes Catholics are part of Christianity. They represent the oldest surviving Christian tradition, along with the Eastern and Russian Orthodox churches. The Protestant movement started by Martin Luther a few hundred years ago, along with England founding its own church (the Church of England or Anglican Church, or as it's known in the US, the Episcopalian Church), resulted in most of the rest of Christianity.

Mormons and Jehovah's Witnesses wish to be considered part of Christianity, but they are very young religions (19th century origins) and hold views considered heretical by most of Christianity and do not subscribe to the accepted doctrinal creeds. Mormonism for example rejects "sola scriptura", the doctrine that the Bible is the only word of god, and adds their own scriptures. The Jehovah's Witnesses reject the doctrine of the trinity and are annihilationsts, meaning they don't believe wrongdoers are punished in hell, but simply cease to exist. This is just a tiny sampling of the offshoot sects and cults with origins in Christianity. (One wag said that a cult is just a religion that isn't old or large enough for people to have gotten used to).

There are a few other religions, some with pretenses to being Christian, some not. Science of Mind, Christian Science, Scientology, and a confusing welter of other ones. There are spiritualists and animists and even people trying to resurrect the old polytheisms like the Norse gods. All sorts of random beliefs out there. Most of them claiming to be right, or more right, or quite often, the only right religion.

By a count of Christian denominations by name and official organization pedigree, there are up to 30,000 of them. By count of denominations that are significantly different from each other doctrinally, there are far less, maybe dozens. You can broadly classify Christians into Catholic and Protestant, or high and low church, or any number of ways. In practice, people move between similar denominations with quite a bit of freedom all the time. They simply pick the "flavor" they prefer. And what they prefer is a function not just of personal preference, but of what they know -- what they grew up with. In fact that is true more broadly of religion. If you are born into a Christian family, you will be a Christian as a child and most likely a Christian your whole life. If you're born as a Muslim or into some obscure animist religion or whatever, then that is what you will most likely be all your life.