Prove??, that scripture gets it's authority from itself, and only through the Spirit it can be understood? Ok, 1Timothy3:16-17 says, "All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work.", and in Romans 8:7 it says, "the sinful mind is hostile to God. it does not submit to God's law, nor can it do so." Those are the precedents of the Bible's internal logic on it's own authority and why it's understood through the Spirit.
Why did God give us the option to continue in life (righteousness) as opposed to death (unrighteousness)? He loves us and wants us to live, as he created us to live.
Why is it wrong to tell God, "I don't want to."? He created us to live, and he'd prefer we chose life as opposed to death. "I don't want to", is death. As an aside, C.S. Lewis wrote a fascinating short story called "The Great Divorce" which describes how people in hell are there willingly, and choose hell over heaven, because they're so sin soaked and filled with pride with "I don't want to's.". Lewis makes his famous quote, "There are only two types of people in this world, those who say to God "Your will be done" and those to whom God says "Your will be done". If God created you, wants you to live well, created you with the intention to live in relationship with Him, there should never be a moment you'll have to say no to a serious request, as he is good by nature. Only deception makes you say no to God, and only Christ can bring you out of that deception, but we can talk about justice and mercy later.
I live in a global village, where there is no "out-group", only one great big "in-group", where there actually is an absolute morality to be found amongst all people due to God's general revelation of himself through creation.
As well, with the continued, "prove it" statements, I don't have to prove with 100% certainty, I just have to make logical arguments that are more logical than their negation. Moral questions are predicated upon something, and I'm simply arguing upon a reasonable ground, otherwise, there is no such thing as good vs evil, but just people, like Richard Dawkings says, "dancing to the strings of their DNA". I just choose the one that gives an ultimate hope and meaning to this life.