While I respect Frank Hoffman's position, I will nonetheless disagree with a few points, and making some qualifications to other.
While I agree with the last statement he made that "We choose to live in the darkness. We choose to live in the light. We choose to do evil. We choose to do good. We choose to listen to God. We choose to disobey God." it is NOT done freely. I say this because we know from behavioural psychology that human beings respond to their environment based on the education they receive from their earliest experiences of people and things around them: thus they are predisposed to a variety of responces concerning a variety of stimuli. (not to mention genetic factors) If you do not believe that human beings are formed and heavily impressed on by their environment, then I would like you to explain how is it you can speak, write, interact and hold the views that you do. I offer that the reason is, is that you were taught to by your environment to do these things. Your views are based on experiences, and experiences are part of the environment. If anyone is wondering "what about inner experiences?" then I would offer that these occured to you via some mysterious power we call "God" or "angels" or what-have-you: an outside force beyond our control. So I do not see how our will to choose is "free". In order for a will to be "free": it cannot be conditioned to behave in a particular manner or have the choice itself conditioned by any stimulus of the environment, or any other factor which stems from any source other than the "self", but the "self" is itself a conditioned, contingent entity. Therefore, there is no such thing as a truly free will "if we are really honest with ourselves".
Adam and Eve were innocent and ignorant upon their creation (Gen 2:25 - they felt no shame, that is, did not judge, which is to be innocent)
Adam and Eve had no knowledge prior to eating the fruit of the Tree of Knowledge (Gen 2:25)
Adam and Eve were told not to eat while in a state of ignorance (Gen 2:17)
Since the ignorant are unable to discern right from wrong (as this is knowledge), the ignorant Adam and Eve were unable to grasp the meaning of "no" or "don't" (just like children). Therefore, they did not know what we can "disobedience" to be wrong. (Since, again, they had no knowledge of good or evil)
The Snake told Eve to eat from the Tree. Since she did not have knowledge of good or evil, she did not know the implications of doing the snakes bidding. So she ate and shared it with Adam.
What does this mean? That Adam and Eve, in actual fact, did not have a "free will" in doing what they did. Nor is our will free either (though we have much more content in our minds and are held responsible for the en-action of that content for the sake of maintaining order in our society - but it is not free).
On another note, you mentioned that "evil" is not a "thing". Since evil is a value judgement about what we experience according to some standard, then I would, in many cases, agree with you that evil is not an object to be examined, rather the indentification and judgement about a particular characteristic of an object. However, using your logic, there is also no such thing as "good" either. That too is a value judgement made about particular characteristics of an object based on some system of values. Since this argument counters the standard Christian understanding of the qualitative values of good or evil, I think it is not helpful to discuss good or evil in this situation as a substance, rather it is best described as state of (spiritual) "knowledge" or "ignorance", if we act according to "ignorance", we are bound to voilate the dignity of other beings in a plethora of ways, "evil". However, if we act from a place of spiriual "knowledge", then we are likely to do what might be characterised as "good". Indeed, we might view this another way: when we act in harmony with things (such as moderation, even handed-ness etc.) then things can be characterised as "good"; however, when we are out of harmony, out of balance, (disregarding the dignity of others, seeking to overstep reasonable social bounds for the sake of our ego) "evil" is done.
Just though I would share a reflection,