the reasons for the Bible are basically, in simplistic form:
1. Salvation of souls for the afterlife;
2. Directions and instructions for living a better life here.
Regarding #2 above: The Bible gives instructions for living a good life here. It is filled with many examples of how God favors people who follow the instructions. It gives many examples of how God is against those people who don't follow the instructions, even though He patiently puts up with them, often for a long time. In addition, it shows how difficult it is to live a life that follows the instructions entirely.
Can you give us some examples of those directions and instructions for living a better life in the bible?
Yes, I can. Well, I think I can. Not knowing the future, maybe if I truly tried, I would find that I couldn't.
So... What are they?
There's the Ten Commandments for starters. They are first written in the book of Exodus, in the O.T. Following them are other rules that make a lot of sense where they apply to us in life.
Of the ten, only five, half, are actually good for late bing a better let me: don't murder, don't commit adultery, don't steal, don't bear false witness against your neighbor, and don't covet. The one about honoring your mother and father are dubious, since people should be honored for what they do, not what they are (what if your father is a violent alcoholic, and your parents generally neglect you?)
What about things like don't rape, don't force people into slavery, don't commit fraud or lie, don't hit people, don't destroy other's property, or even just help others who need it if you're able? Seems like a lot of waste using up the first 4 of those commandments for just vain stuff.
Jumping in here after a month or two.
The first four commandments are about putting God in His proper place and in doing so, a person should then feel compelled to carry out the rest of the commandments out of love for God and then because of understanding who God is, choosing to love others because of that. In today's society there is a belief that we can just choose to love others and skip the first part. But the question of where does our conscience or even knowledge of right and wrong come from? I believe that our conscience is the Holy Spirit speaking to us. We have a voice that tells us what is right and wrong and it is God speaking to us. Many religions have these same sets of laws in them and morality can have a common thread throughout religion and cultures, but where does that common morality originate?
As for the main purpose of the commandments, Galatians 5:14 says: For the whole law can be summed up in this one command: "Love your neighbor as yourself." In reality I believe sin is anything that hurts others. If a person truly loves others he will not be sinning in doing so. If we just stop focusing on what the "rules" are and start having love and compassion for others we would all be doing what God wills for us. However, we get stuck on a list of "do's and don'ts" when they are just there to open our eyes to the fact we all have fallen short of God's law in one way or another and need to humbly come to Him in repentance for that.