Two concepts are considered in this quote: brotherhood and labor. These are two recurrent themes in the Agni Yoga teachings. Like most of the quality teaching that I have been exposed to over the years, the terms have deeper meaning than any initial understanding. "Brotherhood" is an easily distorted concept by humanity, disconnecting it from the meaning in the Agni Yoga books. Likewise "labor." Both of these terms can be understood to be elements of consciousness. For example, "labor" is all too easily seen from a physical point of understanding. Yet there is labor upon other levels of being - thought being the prime field of labor. And this theme will be explored as time goes on.
Meanwhile, this particular quote has reference - for me - to the theme of Triangles (explored elsewhere on Hearts, Incorporated), all the while addressing brotherhood.
"It is not easy to gather together a brotherhood in full concordance. Let i t be a group small in number, but without contradictions; it is easier for a small group both to convene and to separate. Any forcible bond is contrary to the concept of Brotherhood. Let them be only three, yet will their concordance be stronger than the vacillation of a hundred. Hesitation and confusion are injurious not only to people but also cosmically.
"In olden times prolonged testings were designated in order to assemble a nucleus of the spiritually concordant. However, length of time alone does not solve the problem of selection. An evil seed can remain concealed for years and years. The feeling of the heart can whisper the better intimations. Too lightly do people handle a higher concept, and only a few know how to guard it with full love....
"The ignorant, those with overcast hearts, say, 'Such a ladder is nebulous,' because it is not for them to ascend. It is the more necessary to explain about Brotherhood, because soon people will seek cooperation. All encouragement for such cooperation will be needed. Thus, throughout the world respect for work will be manifested. Labor will be an antitoxin against gold. Yet, many times one is obliged to speak about the beauty of toil." Brotherhood, para. 315