September 3

In regard to your question as to whether it is permissible to substitute the plural pronoun for the singular in prayers worded in the singular, the Guardian would strongly urge your N.S.A. to inform the friends to strictly adhere to the text of the Holy Writings, and not to deviate even a hair-breadth from what has been revealed by the Holy Pen. Besides, it should be noted that congregational prayer has been discouraged by Bahá’u’lláh, and that it is allowed only in the case of the prayer for the dead. 
- Shoghi Effendi  (From a letter dated December 17, 1934 written on behalf of Shoghi Effendi to an individual believer; ‘Messages to Australia and New Zealand’)