Taking the story of the feeding of the 5,00 at face value, if Jesus's intention just about sustaining a lot of people there are considerably simpler ways that this could be achieved if one has access to God's omnipotence. For example; the crowd simply happens to have enough food on it or, given that it's by a beach, have fish available in abundance.
The real purpose is to demonstrate (to the reader) that Jeebus has these powers - it's also later used as a call back to supposedly underline J's slightly suspect cannibal/bread issues. The point is certainly not about charity; that merely gives the justification for the demonstration.