Gods supposed perfection

[MistressD]

I guess perhaps I address this question to theists...if God is so perfect, and created Adam and eve as perfect in his image, then why did they disobey him? If they were created without sin then how is it they came to sin? I'm not talking about the stupid tree of knowledge, I'm asking how it was they were so susceptible to satan? Which leads me to another question, God created satan himself, from what I understand he was a perfect angel, then how is it he also came to sin? This seems to me God is in fact fallible, or else deliberately set us up to fail, seeing as how sin should not exist unless he made it so. As a burgeoning atheist, this is one of the biggest issues I have with theism. I wish to hear as many points of view as possible on this one, not just Christians please.