That is why I like one of the Jewish explainations so much better. God knew that Man would be tempted, and eat from the tree of Knowledge of good and evil. It is only by learning, and being able to make both right and wrong choices that someone can learn to make the RIGHT choice.
God set man up, so man would be able to make choices. By choose the good choices, man can be closer to god, and live a more sanctified life.