Answer: In our lives we are in the collisions and interactions with other people and all sorts of germs and viruses are passed from one to another in our life. But precisely because of that we become stronger and build immunity.
The same thing also happens when we fulfill the method of unity. When we work on the ego separately it is harmful, but when we begin to work together and rise above it we find out how helpful it is. It is given as help against us. This is the method of correction that we should study.
We should be grateful for our egoism, because with its help we ascend the spiritual ladder of 125 levels. The higher we ascend the ladder, the more our egoism grows and develops.
It is an amazing process in which the higher a person rises, the more egoistic he becomes and at the same time the more spiritual he becomes. This is how the wisdom of Kabbalah differs from all the other methods because we use all the forces of nature, including the egoistic force. Nothing is left outside my correction. I absorb all the negative and positive forces and unite them in a symbiosis, a special bundle, thanks to which I ascend the spiritual ladder.
From the Kabbalah Lesson in Russian 11/15/15