it seems that many self-proclaimed Christian organizations try to persuade people that, by suffering a loss and having some other people gain something from it, you will receive some mystical benefit. The underlying assumption seems to be that interactions for mutual benefit aren't possible.

Note that giving money to others involves a (monetary) loss to you, but doesn't necessarily help others. For example, the gift money could be used for illegal and impure drugs, creating health problems or death for the user, and providing another increment to the income of criminal organizations in various parts of the world.

Also note that mutual harm is not particularly obscure. It's obviously possible for wars between nations and smaller scale physical conflicts to produce no net gain for anybody. Thus, it's obviously possible that a loss for one person could be associated with an event that benefits nobody.

The obvious and sensible approach to human interaction is to avoid interactions in which anyone would suffer a loss of any kind, and to pursue interactions in which everybody gains. This is well-known in sales training. Sales managers who encourage integrity selling tell their sales employees to aim for a transaction in the "win-win" quadrant.

The alternative "golden rule" philosophy relies upon a completely unspecified analogy. Do unto others how? As you would have others do unto you. However, the word "as" there merely signals that there is to be some kind of analogy. Who can say whether or not an alleged analogy is actually an analogy? Who can say whether or not a given analogy is a good analogy?

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