Arise thou to serve the Cause of thy Lord; then give the people the joyful tidings concerning this resplendent Light whose revelation hath been announced by God through His Prophets and Messengers. Admonish everyone moreover to observe prudence as ordained by Him, and in the Name of God advise them, saying: It behoveth every one in this Day of God to dedicate himself to the teaching of the Cause with utmost prudence and steadfastness. Should he discover a pure soil, let him sow the seed of the Word of God, otherwise it would be preferable to observe silence.
(Baha'u'llah, Tablets of Baha'u'llah Revealed After the Kitab-i-Aqdas)