We should adhere to the spiritual laws revealed to humanity in each age by the Manifestation of God the same way that we pay attention to laws governing our physical lives

Just as there are laws governing our physical lives, requiring that we must supply our bodies with certain foods, maintain them within a certain range of temperatures, and so forth, if we wish to avoid physical disabilities, so also there are laws governing our spiritual lives. These laws are revealed to mankind in each age by the Manifestation of God, and obedience to them is of vital importance if each human being, and mankind in general, is to develop properly and harmoniously. Moreover, these various aspects are interdependent. If an individual violates the spiritual laws for his own development he will cause injury not only to himself but to the society in which he lives. Similarly, the condition of society has a direct effect on the individuals who must live within it. (The Universal House of Justice, from a letter dated 6 February 1973 to all National Spiritual Assemblies; ‘Messages from the Universal House of Justice 1968-1973’; The Compilation of Compilations, vol. I, A Chase and Holy Life)