As you can see, all these developments relate directly to the teaching work inasmuch as the Bahá’í communities must reach a certain size before they can begin to implement many of them. How, for example, can a Bahá’í community demonstrate effectively the abolition of prejudices which divide the inhabitants of a country until it has a cross-section of those inhabitants within its ranks? A seed is the vital origin of a tree and of a tremendous importance for that reason, but it cannot produce fruit until it has grown into a tree and flowered and fruited. So a Bahá’í community of nine believers is a vital step, since it can bring into being for that locality the divine institution of the Local Spiritual Assembly, but it is still only a seed, and needs to grow in size and in the diversity of its members before it can produce really convincing fruit for its fellow citizens.
(The Universal House of Justice, Messages 1963 to 1986, p. 515-516)