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