It's fairly easy, if you think god is all powerful and knows everything, the bible can be logically disproved. An all powerful, all knowing god would not get mad and kill everyone because he 'failed', he can't fail, he can't be mad, he can't have our feelings.
God cant fail we can. We can fail because we have been given freedom. Our choices are not compelled.
This article had a nice summary on this topic.
Gods Angerby Caleb Colley Ph.D.
http://www.apologeticspress.org/APContent.aspx?category=12&article=1462''Gods anger is rationally retributive. His anger is His direct, calculated response to sin.''
Actually, his 'anger' is nothing but rational. Consider this example, you know everything, you can do anything. A rock falls on your friend and kills him, do you get mad? Of course not because you could have prevented it, you allowed it to happen and you already knew thousands of years ago that it would happen so there is simply no logical reason to get mad. I understand humans have free will, so what? God created them that way and knew what would happen so again, no reason to be mad.
Also big logical inconsistencies, god wanted us to have free will but he himself killed millions.