Do not be surprised that a single person can, through his actions, cause the entire world to ascend or descend. For there is a fixed rule: the macro and the micro are the same, like two drops of water. Anything that occurs at the macro level happens at the micro level. The opposite is also the case. The micro acts upon the entirety of the macro. The macro will not be fully revealed until all of the micro is revealed as well, proportional to the measure and quality of each element in the micro.
One Person's Actions Can Raise or Lower the World
Baal HaSulam's Introduction to Zohar 68:1