They disobeyed God by eating from the Tree of Knowledge of God and Evil. So, yes... Right?
Wrong. How could Adam and Eve have been expected to comprehend the implications of their actions if, prior to their indiscretion, they had no concept of wrong, evil, punishment, suffering, pain, and death? Even if God has been successful in adequately explaining all of these concepts and the distinction between right and wrong to them beforehand, this means that he would have had to have given them knowledge of good and evil anyways, which turns this entire story into one big ridiculous farce.
A just, loving, and secure god would realize that simply not believing in him is NOT a crime worthy of hellfire.
Bonus points who can identify the origin of this screen shot.