What I've learned, the hard way, is that when He sends surplus in your direction, it is always with the intention that what comes to you will flow through you into the hands of those who are going to need it in the future. Look at the story of Joseph in Genesis. Egypt was given 7 years of incredible surplus in their harvest because God wanted that surplus to be used to feed EVERYONE around them for the 7 years of famine that would come next. You can find this story in Genesis chapters 41-43. If not for Joseph's wisdom in how he handled that surplus, not only would the Egyptian people have suffered but the entire fledgling tribe of Israel might have died out as well.
Prosperity is intended to flow like a river, from the hands of one to the hands of another. When it flows like it is intended to flow, it reaches from one region to another and everyone flourishes and everyone thrives. Contrary to what most people fear, nobody is harmed by other people gaining prosperity. It helps everyone and improves the lives of everyone.
What stops the river from flowing is the dams we build through our sinful choices and decisions. When we allow fear to guide us to clinging to the prosperity instead of spreading it out, when we allow our greed to cause us to keep the prosperity to ourselves and even take away what little others have, when we are guided by selfishness and self-indulgence rather than consulting God on His purpose and plans for the prosperity we've achieved, we become like a dam that stops the flow of the river. We prevent it from reaching the people it was intended to reach.
If enough people are damming the river with their selfishness and sinfulness, the fertile land becomes dried out and unable to sustain anyone downstream of the dam. God must literally force the dams to break in order to restore life to those who have been suffering, but this process is painful and causes a lot of pain before the equilibrium is restored and things return to the way they were supposed to be.
A real life example of the negative effects of damming rivers on populations downstream from the dams can have is the Colorado river. Once upon a time, that river flowed without any hindrance, watering the states from Colorado down to Nevada and Arizona and into Mexico with fresh water. It was a critical water source. However, because of so many dams being built to siphon off water and to harness it for energy, the water by the time it reaches Mexico is full of salt and of poor quality for drinking. Those at the end of the Colorado river are being robbed of the prosperity that was meant for them because of the selfishness of those at the upper ends of the river.