Kabbalists write that a soul is a vessel to be filled with the upper Light. Every person has to attain the root of his soul, for this is the sole purpose of his life. The Creator created only one soul. It broke into multitude of pieces, the so called individual souls, each correcting only itself to ease the collective correction. In general though, there is only one soul for all. Baal HaSulam writes about it in his article “Six Hundred Thousand Souls.” Therefore, all the people being a part of a single soul have to help each other reveal it, attain it, and enter the state of eternity, perfection, infinity, exactly as our Creator.