O God! We pray that from now on, Thou, the Beloved
will bestow upon Shoghi Effendi all the strength and
vigor that will enable him to pursue over a long unbroken
period of strenuous labor, the supreme task of achieving,
in collaboration with the friends in every land, the
speedy triumph of the Cause of Bahá'u'lláh.

This was adapted from his letter dated the 14th of November 1923

I cherish the hope that, from now on, the Beloved may bestow upon me all the strength and vigor that will enable me to pursue over a long and unbroken period of strenuous labor the supreme task of achieving, in collaboration with the friends in every land, the speedy triumph of the Cause of Bahá'u'lláh. This is the prayer I earnestly request all my fellow-brethren and sisters in the Faith to offer on my behalf.

He also had a prayer for the believers:

"Let us pray to God that in these days of world-encircling gloom, when the dark forces of nature, of hate, rebellion, anarchy and reaction are threatening the very stability of human society, when the most precious fruits of civilization are undergoing severe and unparalleled tests, we may all realize, more profoundly than ever, that though but a mere handful amidst the seething masses of the world, we are in this day the chosen instruments of God's grace, that our mission is most urgent and vital to the fate of humanity, and, fortified by these sentiments, arise to achieve God's holy purpose for mankind."