Personal pronouns referring to the Manifestations of God or to Abdul Baha should invariably be capitalized!

February 3. On this date in 1975, the Universal House of Justice wrote "In English translations of the Sacred Bahá'í Writings personal pronouns referring to the Manifestations of God or to 'Abdu'l-Bahá should invariably be capitalized; in the Guardian's writings in English his own style must be followed. Capitalization of pronouns relating to the Manifestations of God and to 'Abdu'l-Bahá in introductory books or books about the Faith in the English language is left to the personal choice of the author."

In English translations of the Sacred Bahá'í Writings personal pronouns referring to the Manifestations of God or to 'Abdu'l-Bahá should invariably be capitalized; in the Guardian's writings in English his own style must be followed. Capitalization of pronouns relating to the Manifestations of God and to 'Abdu'l-Bahá in introductory books or books about the Faith in the English language is left to the personal choice of the author. (3 February 1975)

https://bahai-library.com/uhj_mihdi_pronouns_english