Let me begin with a definition of zero-sum thinking with regard to wealth, which I have referred to in this space a number of times. Zero-sum thinking assumes (in unbelief) that the amount of available blessings is necessarily fixed, and that it therefore follows that if one man gets a larger piece of the pie, others have to get a smaller piece. A wonderfully succinct summary of this mentality is found on the bumpersticker "Live Simply So That Others Can Simply Live." Anyone who agrees with that bumpersticker, or is in sympathy with it, is in the grip of zero-sum thinking. More on that in a moment.
Now the problem with zero-sum thinking is that it conflicts with the triune nature of God, as expressed in the way He determined to make the world. We ought not be distracted by the fact that certain libertarian secularists have noticed the problems with zero-sum thinking, just as other secular scientists have noticed that things fall down when you drop them. They have noticed this; because they are idolaters, they cannot account for it. As Trinitarian Christians, we can account for it -- the triune God overflows into His creation. He would not have made a Malthusian world in which consumers reproduce like crazy while resources dwindle (and when that has happened in certain local populations, it is because of sin, not creation). So God is not like that. Even if you accept the dogma of the conservation of matter and energy, His addition of time and history makes the whole created order an everlasting increase, world without end, amen.
But sin is like that. Sin is blinkered and it naturally and easily assumes, in the grip of envy and covetousness, that more for him is less for me, and since I am in this for me, we have to work on more for me and less for him, and devil take the hindmost. Theft and fraud are driven by zero-sum thinking, which is one of the underlying theological reasons for opposing and rejecting them.
There are three kinds of wealth -- blessed wealth, sinful wealth, and criminal wealth. Since the Lord did not see fit to create a world made up of isolated, watertight compartments, there will obviously be some traffic or overlap between the categories from time to time. At the same time, the categories are distinct and real, and we should labor to use them. Blessed wealth is from the hand of God (Dt. 8:18). Sinful wealth is wealth that is obtained in external conformity to the laws of God, but with the motives all screwed up. Like a man who marries a beautiful woman for all the wrong reasons, his action is lawful (and not to be called adultery or fornication) but God still sees and judges his sinful motives (1 Thess. 4:4-5). Sinful wealth is legal and everything, but God will still judge the heart. There is no indication that the rich fool who wanted those bigger barns had broken any laws (Luke 12:18). For my stipulated set of distinctions here, I am defining sinful wealth that which could be legally acquired with impure motives in a just society.
And criminal wealth is wealth that is obtained in ways that would violate the laws of any just society. This wealth could be obtained in open defiance of the laws (a highwayman), or surreptitious defiance of them (securities fraud), or in open compliance with wicked laws (eminent domain). Criminal wealth is the kind that could be confiscated and returned to the victims after a fair trial.
So when a man with criminal wealth is converted, his duty is to make restitution (Luke 19:8). The money is not his, and conversion doesn't make it his. When a man with sinful wealth is converted, he should receive God's full and free forgiveness for all his sinful motives, and treat his wealth from that point on as though it were blessed wealth, which it now is. This means giving from that wealth out gratitude. Just like the man who married a woman for the wrong reasons, God is picking him up from where he is, and not from where he should have been. He is not in possession of the wealth of others -- he is in possession of his own wealth, concerning which he used to have a wrong attitude. And the man with blessed wealth should simply follow the instructions of the apostle (1 Tim. 6:17-18). Be generous, willing to share, overflowing to others. The first gives out of necessity and obligation -- restitution is mandatory. The latter two are to give freely and cheerfully, abundantly, out of gratitude, not guilt.
I have said before that God hates it when people give out of guilt instead of generosity. But this obviously does not apply to restitution. Restitution is mandatory because of objective guilt for objective crimes. Guilt is a reality, but only for things that God identifies in His law as sinful. The mere possession of more than what others possess does not fit in that category. Restitution is not to be made in the form of gifts -- it must come as restitution. And gifts must not be treated as though they were restitution.
When people begin assuming that the mere possession of wealth is a crime (which is contrary to the nature of God and all His laws), all their giving is soon dislocated by the pressures of guilt. This is what zero-sum thinking does. It dislocates everything in the name of making everything whole.
But it involves more than an economic fallacy. I have said before that when giving is motivated by guilt, the giving will be just enough to make the guilt subside, which is usually around twenty bucks. When someone learns to give out of gratitude, they are participating by faith in the triune life, and they never stop giving. It becomes part of their nature to give, and they do so in sustained ways, throughout the entire course of their lives.
So what is involved beyond the fallacy? Well, if the rhetoric is to be believed (as I do not, but which the zero-sum thinker claims to), living simply is not nearly enough. And if a slight diminution of hypocrisy is identified as though it were a real repentance from hypocrisy, the result is really an amplified hypocrisy -- or accentuated confusion. Let me explain how that works.
Suppose we have ten men around a table, and six of them have just a sliver of pie and they are going to starve, one has half the pie, the other three have fairly sizable pieces. Now we have different visions of what is exactly going on here, but if you are zero-sum thinker, you believe that the guy with half the pie is the biggest part of the problem, and the other three (including yourself) are major contributors to the problem.
If the logic is right (it isn't, but work with me here), it is not anywhere near enough to "live simply that others might simply live." If people around the world are starving to death every minute, and if it is our fault that they are doing so, how does it address anything to live fifty times better than they do instead of a hundred times better? And why on earth do we put up with the fifty-times-better fellows upbraiding us for our fifty to a hundred-times-better lifestyle? That bumpersticker is on the bumper of a car, remember, the value of which represents a lifetime of income for multitudes around the world. So sell the car, champ. If the logic were right, it would be necessary for every Christian to simply live so that others could simply live. But this relentlessly consistent conclusion does not appear to be held by anybody. How many poverty agitators live under bridges in cardboard boxes? So that others might simply live? I bet you could find a handful, but they would only be there for a very short time -- until they landed that lucrative book deal that relates their harrowing experiences to an astonished public.
So either: 1. the logic of zero sum thinking is wrong, and one man's blessing need not be related at all to another's poverty; 2. or the logic of zero sum thinking is right, and 2a. its advocates are the biggest hypocrites on earth, or 2b. they are hopelessly confused, but in a way that almost always and luckily retains a hefty piece of pie. In my experience, 2b is usually the way it goes.
If having a bigger piece of piece of pie is tantamount to starving people to death, then the fellow with a quarter of the pie (who actually says he believes that) needs to be able to come up with something better to do than lecture another guy with a quarter piece who doesn't believe it. But if he proceeds with his lecture anyway, the auditor of the scolding should just pick up a fork and say, "I'll think about acting like I believe all that when you starting acting like you believe it. And no, shaving off slivers doesn't count. People are dying, man."