One Mind means one Mind,—not one bit of mind communicating or imparting to another bit. Not one bit treating another bit. One Mind constitutes of itself all thought, feeling and action.
Because all is Mind there is nothing outside to respond. In the definition of Gethsemane we read of “…love meeting no response, but still remaining love” (S&H 586:23) and you remember that when the disciples did not support Jesus for even one hour, she says “There was no response to that human yearning…” (S&H 48:7). He learned the great lesson that idea is responsive to the Mind that has the idea, and not to anything external to itself. There are no human demands, debts, or obligations. Just infinite Love, the one Mind, unfolding itself as all.
In the Sunday School, the same could apply. You do not know how your own gentle presence just permeates the class, and unless someone is being positively disruptive—in which case they should be in a class alone—you do not feel you are not succeeding because there is no response.
Adhesion belongs to God. (See S&H 124:20-21) Nothing can adhere to God but good. There is no personal attachment—nothing to attach itself to person. But the great thing is not to be self-conscious about something, even if others remark on it. I have known so many cases where some growth or other has dropped away without the person being aware of it.