"I guess greed ought to be carefully defined. The Good Book doesn't really help us in this regard."
I believe that it does. In fact, it often defines and equates greed specifically with idol worshiping, or idolatry.
The biblical texts speak of tov versus ra, that is - function versus dysfunction, balance versus imbalance, perfect versus imperfect - good versus bad [if you must so use these terms].
Desire is a human instinct, or trait; in fact, a necessary one. For example - one desires to breath, to eat, to drink, to companionship, to rest, to work, and so on. Each one of these basics, however, requires a balanced view in order to prove functional [tov]. To eat is good. Eating supplies the human body with nutrients and other substances required to maintain life. Eat too little and you will become dysfunctional [ra] relative to life [e.g., you may even eventually die from not having eaten enough] - eat too much and you will also become dysfunctional [ra] relative to life [e.g., you may eventually die as a direct result from overeating]. To drink water is good - not enough water and you will suffer, perhaps even die from dehydration. Conversely, drink too much water, and you could place your very life at significant risk [wasn't there a young women somewhere recently who died as a direct result of drinking too much water in some sort of a contest?]. Function versus dysfunction, balance versus imbalance, and good versus bad.
Desire itself is no different than these things. If you do not have sufficient desire for the elements which sustain life you will suffer, die even, as a direct result. If your desire for such things is too strong [e.g., “greed”], you will also suffer, and possibly lose your life.
A small campfire which cooks food is quite functional; an out-of-control raging inferno which consumes the entire forest as well as the campground would prove quite dysfunctional for the purpose of cooking food.
Control seems to be a central issue from the biblical perspective. You know the sayings … “Do you work to live, or live to work” … “Does money serve your immediate needs, or do your needs serve money”.
In Ephesians 5:5 Paul states, “For you know very well that no immoral or impure person, or anyone who is greedy (that is, an idolater), has an inheritance in the kingdom of the Messiah and of God”.
The koine Greek word used by the author here for the English translated “greedy” is pleonekteô, which simply means “to have or claim more than one's due, to get or have too much, to be greedy, grasping, and even arrogant”. He even goes as far to claim that being greedy is equivalent to being an idol worshiper, idolater - e.g., ho estin eidoloatres.
Desire serves the human existence; greed on the other hand, is when the human makes desire his or her master. This condition falls outside of the original intent, function, and purpose for the human being - a path not intended for travel [by definition then, this is khate, or "sin" if you will] - be on it intentionally with full knowledge, and the bible calls you rasha. The Hebrew and Christian Greek Scriptures pretty much make clear the admonishment relative to being an idol worshipper [Exodus 20:3 for starters].
Greed [desire out of control] may also indicate that the person does not trust Yhwh to make good his promise made all what is needed will be supplied [Matthew 6:33] to those placing their full trust in him. In a sense, greed could be easily conceived as “turning away from Yhwh” - and in this sense, the bible classifies it as "idolatry" as well.
Jesus seems to have provided a similar warning to Paul’s as he commands his followers to guard against longing for something that we do not have, "Keep your eyes open and guard against every sort of greed, because even when a person has an abundance his life does not result from the things he possesses" [Luke 12:15]. Here, the author employs “pleonexia”, which is the conduct and character specifically of a pleonektês - e.g., greediness, grasping, assumption, arrogance, et al.
This verse, and his subsequent illustrations, seems to demonstrate that greed is based on the foolish foundation and principle that what matters in life is how much one has, be it money, food, attire, power, status, et al. To engage in such practice, demonstrates the condition of a person’s “heart condition”, or the “authority within”, the lev, and is the very basis upon which one is judged by Yhwh, as it demonstrates a person’s trust toward Yhwh and the placement of themselves as being equal or higher in position relative to their own creator [see Genesis Chapter 3]. Does Jesus himself not conclude specifically in Luke 12 that only Yhwh can, and will, serve to satisfy our needs as living, breathing, creatures?
