However much the need may be for physical healing, the supreme need of the world today is for spiritual healing. Life in this world is so relatively short—and at present it is fraught with a thousand difficulties and dangers; whereas life in the true sense is eternal, and for this eternal life people need some preparation in these turbulent times. Your work to improve the health of the people is a meritorious way of serving mankind, but it can never be compared with the work of illumining the souls and minds of men with the Light of Bahá’u’lláh. The people of the world are teeming millions, the Bahá’ís only a handful, yet they are the precious leaven that must leaven the lump.
(Shoghi Effendi, Lights of Guidance, p. 279)