This happened because WE messed up. Adam and Eve sinned in the Garden of Eden. Why did this happen? Because God made us in his own image. He gave us the power of free thought. Science will also agree the most significant difference between man and animal is that man is sentient and can think for himself. "I think, therefore I am.", yes? But Adam and Eve, when tempted by Satan, just did not have the will to resist temptation (which, by the way, Adam and Eve were also to blame, not just Satan). And so humans fell from righteousness. Humans, even before Adam and Eve sinned, were NOT perfect, as only God can be perfect. In a similar way, an artist can create his masterpiece. It is good, better than any of his other creations, yet the paintING can never be compared to the paintER.