Although you seem to feel that your prayers have not so far been answered, and do no longer have any hope that your material conditions will ameliorate, the Guardian wishes you nevertheless not to allow such disappointments to undermine your faith in the power of prayer, but rather to continue entreating the Almighty to enable you to discover the great wisdom which may be hidden behind all these sufferings. For are not our sufferings often blessings in disguise, through which God wishes to test the sincerity and depth of our faith, and thereby make us firmer in His Cause?
(Shoghi Effendi, The Compilation of Compilations vol II, p. 239)
Every supplication for divine assistance offered by the faithful, has released, and will continue mysteriously to release, forces over which no antagonist of the Faith has any control, and which, as marshalled by an All-Watchful Providence, have served to noise abroad the name and fame of the Faith to the masses of humanity in all continents, millions of whom had previously been totally ignorant of the existence of the Faith or had but a superficial, and oft- times erroneous, understanding of its teachings and history.
(Universal House of Justice, The Compilation of Compilations vol. I, p. 167)
The prayers which were revealed to ask for healing apply both to physical and spiritual healing. Recite them, then, to heal both the soul and the body. If healing is right for the patient, it will certainly be granted; but for some ailing persons, healing would only be the cause of other ills. And therefore wisdom doth not permit an affirmative answer to the prayer.
(‘Abdu’l-Bahá, Selections from the Writings of ‘Abdu’l-Bahá, p.161-162)
Who is there that hath cried after Thee, and whose prayer hath remained unanswered? Where is he to be found who hath reached forth towards Thee, and whom Thou hast failed to approach? Who is he that can claim to have fixed his gaze upon Thee, and toward whom the eye of Thy loving-kindness hath not been directed? I bear witness that Thou hadst turned toward Thy servants ere they had turned toward Thee, and hadst remembered them ere they had remembered Thee. All grace is Thine, O Thou in Whose hand is the kingdom of Divine gifts and the source of every irrevocable decree. Send down, therefore, O my God, upon all that seek Thee that which will entirely strip them of all that pertaineth not unto Thee, and will draw them nigh unto Thy Self. Assist them, by Thy grace, to love Thee and to conform unto that which shall please Thee. Grant, then, that they may go straight on in the path of Thy Cause, the path wherein have slipped the footsteps of the doubters among Thy people and the froward among Thy servants.
(Bahá’u’lláh, Prayers and Meditations by Bahá’u’lláh, p. 253)