April 6

O ye apostles of Bahá’u’lláh! May my life be sacrificed for you!... Behold the portals which Bahá’u’lláh hath opened before you. Consider how exalted and lofty is the station you are destined to attain; how unique the favors with which you have been endowed... The full measure of your success is as yet unrevealed, its significance still unapprehended. Ere long ye will, with your own eyes, witness how brilliantly every one of you, even as a shining star, will radiate in the firmament of your country the light of Divine Guidance, and will bestow upon its people the glory of an everlasting life.... The range of your future achievements still remains undisclosed. I fervently hope that in the near future the whole earth may be stirred and shaken by the results of your achievements. The Almighty will no doubt grant you the help of His grace, will invest you with the tokens of His might, and will endue your souls with the sustaining power of His Holy Spirit. 
(‘Abdu’l-Baha, quoted by Shoghi Effendi in a letter dated June 15, 1946; ‘Messages to America’)