Answer: The role of the Kabbalistic group is similar to that of family, friends, relatives, social security, and medical insurance in our life. If I’m in a tough situation, fall ill, or lose my job, there is a system that helps me in that weak moment.
This system of mutual support in spiritual development is called "mutual guarantee" (Arvut). The speed and ease of our advancement toward the goal – the revelation of the Creator – depend upon the strength of this system. It influences everyone, and its strength accumulates as a result of our common efforts.
Rabash writes: “We have gathered here to establish a society for all who wish to climb the degrees of man (Adam), and not remain as a beast.” When we make a joint decision to follow the method of Baal HaSulam, rise above our egoism, and reveal the Creator in the connection between us, we are already making an agreement.
We have to help each other to value the greatness of the goal and the Creator, seeing all the friends as the greatest in the generation, inspiring them with the greatness of the spiritual goal, and realizing our own insignificance. I guarantee to the friends that I will help with this, regardless of what state I am in. These are conditions of our agreement.
Following this, there can be two states:
1. Either I support the group in inspiration, power, unity, and the greatness of the Creator,
2. Or as soon as I become weak, they begin caring for me.
It’s like two communicating vessels. The moment a drop of water is removed from one of them, the water immediately flows into it from the other one, and the water levels always even out in them. The width or volume of each vessel does not matter: If they are connected, the water level will be the same in both.
This is how we are connected in the group. They give me strength, and I give strength to them. It’s impossible to advance without such a mutual guarantee.
From the Lesson on Rabash’s Article, 9/17/10