Not to modify the Writings
From Bahai9
Pronouns should not be changed in Bahá’í prayers (nor any other single word)[edit]
"Regarding your question as to the changing of pronouns in Bahá’í prayers: The Guardian does not approve of such changes, either in the specific prayers or in any others. They should be read as printed without changing a single word."
- (From a letter written on behalf of the Guardian to the National Spiritual Assembly of the United States and Canada, April 13, 1944: Bahá’í News, No. 171, November 1944, p. 3, in Lights of Guidance, no. 1495)
One may not change plural for singular in prayers[edit]
"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."
- (From a letter written on behalf of Shoghi Effendi to the National Spiritual Assembly of Australia and New Zealand, October 17, 1934, in Lights of Guidance, no. 1496)
One may quote a portion of prayers (even short), but should be as is[edit]
"In quoting prayers any part may be used, but should be quoted as it is, however short."
- (From a letter written on behalf of Shoghi Effendi to an individual believer, November 19, 1945: Bahá’í News, No. 210, August 1948, p. 3, in Lights of Guidance, no. 1497)