April 15

...rest ye assured in the confirmations of the Merciful and the assistances of the Most High; become ye sanctified above and purified from this world and the inhabitants thereof; suffer your intention to become for the good of all; cut your attachment to the earth and like unto the essence of the spirit become ye light and delicate. Then with a firm resolution, a pure heart, a rejoiced spirit, and an eloquent tongue, engage your time in the promulgation of the divine principles... (‘Abdu’l-Baha, "Tablets of the Divine Plan Revealed by 'Abdu'l-Bahá to the North American Bahá'ís"; The Compilation of Compilations, vol. II, Guidelines for Teaching)