Tanya Chapter 37 part 4

When the vital soul of all of Israel is elevated to holiness, it will become a chariot for Hashem. This in turn causes the kelipat nogah life energy of the whole world to become elevated, a chariot to Hashem as well. Once the intermediate kelipah –– kelipat nogah –– ascends to holiness, all impurity and negativity will be totally obliterated, no longer having access to life energy. How does the refinement of our own vital soul bring elevation to the whole world? Because the Jewish soul is the source of vitality of the world, and each part of the world is connected to and dependent upon a particular soul. In fulfilling our mission in Torah and mitzvos, we elevate that part of the world which was created solely to support our Divine mission.