The basics of the Christian faith really are, well, basic.
1) Jesus was the son of God
2) He was sent to earth to die in order to save us from our sinfulness
3) He was resurrected after three days
If you believe in those things, believe that Jesus is your savior who died on the cross for your sins, if you are sorry for your sins and want Jesus to enter (or be in) your life to turn your heart away from sinfulness and toward God - then you are a Christian.
All the rest of the "details" are often debated between denominations and worldviews, but for the most part they are unimportant to whether or not you are a saved Christian.
As for the Bible, I'll tell you my personal reason why I think it's important. We all grow up being taught certain things, and we all have our own personal set of beliefs about God, Jesus, religion, etc. But for me, it wasn't enough to be taught something and to believe it just because it's how I was raised. I wanted to know WHY I believed something. I wanted my beliefs to be based on something.
Some people just make stuff up as they go along. They'll say, "Well I don't believe God would do this" or "I don't think a loving God would allow that to happen". But they don't have a solid reason why they feel this way. It's just a feeling, a belief, a notion that isn't based on anything but emotion and instinct. A lot of religions are formed this way, but that doesn't make them true just because they seem to be instinctually based on common emotions or feelings.
The Bible has a lot of evidence for truth in it. There are prophesies in the Old Testament that were fulfilled in the New Testament, hundreds or thousands of years apart. There are things about God and his laws, his requirements, his nature, that go against our human instinct of what God "should" do - but when you delve into it, there are reasons and instructions and warnings right there for us to see. The Bible tells us how God is, what he wants from us, what he's done for us. It tells us how we can get his blessings, how we can love each other better, and the work he wants us to do. It gives us the GOOD NEWS about Jesus and the salvation his death provided us.
I wanted to know about the Bible so that I would have something to base my faith on besides my own emotions, feelings, instincts, and the things other people told me as I was growing up. If I was going to have faith in God, I wanted it to be because I had a good, solid, logical reason for having faith in God. I didn't want to wing it. I wanted to know the truth, and the Bible gives me that.
It IS hard to understand a lot of times. I've only been a Christian for about a year and a half, and I do struggle with a lot of it, especially the Old Testament. I'm lucky that I have some really good teachers at my church that have helped me through Sunday School classes, Bible Studies, and our Home Fellowship Group. I've also found some wonderful (and free) Bible software with some excellent commentaries that help me study and understand on my own.
Marmaladegirl, I know there are people on CF who would be happy to help you understand the Bible better. I'm no expert by any means, but I'm happy to help in any way that I can. The Advice forum and the New Christians forum can help. If there is anything I can do to give you a hand understanding something, I hope you'll feel free to ask. I think it could help clear up a lot of your confusion.
