This is always enough for me to reject fundamentalism. What we have is a supposed God who:
1. Created people with the ability to tell right from wrong, and the ability to reason and understand.
2. Acts in a manner contrary from what we naturally know is right and wrong, and contrary to reason.
Even if you could prove that such a diety actually exists, I'd still deny him.
God did not create man with the ability to tell right and wrong. God created man to trust and obey Him and man ignored the only rule or warning God gave them, not to eat from the tree of the knowledge of good and evil.
Now at first, this seems like some sick trick God played on humanity, but it's more that God indeed gave man freedom including the freedom to know what God knew. God did not make man to know good and evil, that was not his intentions... His intention for man is relationship with man, where man trusts what God says and lives a simple life of prosperity, such as it was in the garden of Eden. However, sin is a matter of the soul, not so much breaking rules. For a man does what he knows is evil, or doesn't do what he knows is right, for that man it is sin. This knowledge creates shame and fear, which inevitably leads man to flee from God. As God is the source of man's life, this leads to death of man.
Satan introduced the original lie, suggesting that God was being selfish and trying to keep man from becoming like Him by warning them not to seek to know good and evil for themselves. This manifests pride in man, as man thought "I'll ignore God's warning. Why shouldn't I be God too?" This is the same thought Satan had, being the greatest angel just below God, however, God would not spare Satan and the devil has no better destiny than to lie, murder and destroy everything else. Misery loves company.
Which criterium, other than the circular "it's in the Bible", should I use to choose between the Bible, the Quran, the Bravagad-Gita, the God Delusion? All of these books have been written by (one or more) imperfect human beings. Except for the God Delusion, all of them claim to have been inspired by a god. Which religion should I adhere? How do I choose? I WANT to do good, you know, I want to do God's will. I just don't want to do the will of a false god - I guess God wouldn't like that, either. I don't want to spend all my energy trying to be a good Christian and then see that I actually should have been a good Muslim.
The reason we know Christianity is true (from God) and other religions (although Christianity is an antithesis to religion if anything) are false (man-made) is that no man would ever invent such a view of God that is Jesus Christ. All other views of God are built on man reaching up to God through performance. This does indeed paint God as a demented being who sits on top and insist we "save ourselves" by climbing up. Christianity says, we are fallen and can't get up on our own, and God because He loves man and is wise of our fallen state, provides the means for redemption by coming to earth as Jesus. Jesus, like a true hero, personally settles the account and pays for it with His life. He conquers satan, our sin/seperation, and the death-effect of sin by rising from the dead.
Christianity answers the "sin problem" with not religion or trying to be better or anything like that, which doesn't really work anyways, but it answers it with faith and trust in God, which is what was broken when made separated himself from God in the beginning of creation (see above). There is no such thing as a "good Christian", in fact to become a Christian you have to "get real" with God and tell him you are also aware of the shame/guilt/sin/whatever in your soul as He is and request it be taken care of for you by His provision of Jesus Christ. Yet again, God proves Himself totally loving and like a perfect father, provides everything. We don't have to do anything but receive it, like you would a gift on Christmas. When you get a gift from someone you don't break out your wallet to pay for it yourself... you just open it.
Such it is with Jesus, and this is what no other view of God or religion includes: redemption is based solely on what God did for us (Jesus) rather than what we can do for God, as if God needed us.
Don't get me wrong, after one comes to faith, there is good works and good fruit, but this is an inevitable aftereffect of faith in Jesus Christ and a joy rather than a burdensome responsibility. These works, too, are prepared in advance for each person if he or she comes to Christ. God provides everything, He asks that we only trust and believe in Jesus.
In this way, Christianity account for other religions... we can see the pattern of the original lie "man become God by knowing good and evil" manifested in world religions. God actually hates religion more than He hates rebellion because it makes an even greater attempt to establish oneself apart from God, ultimately leading to further death of man whom God loves.
If you're interested, here are some web-sermons by a pastor Mark Driscoll of Seattle's Mars Hill Church who breaks it down well.
Vintage Jesus