Titles of Bahá’u’lláh

He was formally designated Bahá’u’lláh, an appellation specifically recorded in the Persian Bayán, signifying at once the glory, the light and the splendor of God, and was styled

• the “Lord of Lords,”
• the “Most Great Name,”
• the “Ancient Beauty,”
• the “Pen of the Most High,”
• the “Hidden Name,”
• the “Preserved Treasure,”
• “He Whom God will make manifest,”
• the “Most Great Light,”
• the “All-Highest Horizon,”
• the “Most Great Ocean,”
• the “Supreme Heaven,”
• the “Pre-Existent Root,”
• the “Self-Subsistent,”
• the “Day-Star of the Universe,”
• the “Great Announcement,”
• the “Speaker on Sinai,”
• the “Sifter of Men,”
• the “Wronged One of the World,”
• the “Desire of the Nations,”
• the “Lord of the Covenant,”
• the “Tree beyond which there is no passing.”

- Shoghi Effendi  ('God Passes By', chapter 6)

Bahá’u’lláh’s name at birth

In the name He bore He combined those of the Imám Ḥusayn, the most illustrious of the successors of the Apostle of God—the brightest “star” shining in the “crown” mentioned in the Revelation of St. John—and of the Imám ‘Alí, the Commander of the Faithful, the second of the two “witnesses” extolled in that same Book. 

- Shoghi Effendi  (God Passes By, chapter 6)

Bahá’u’lláh’s relation to Jews, Christians, Muslims, Zoroastrians, Hindus, and Buddhists

To Israel He was neither more nor less than the incarnation of the “Everlasting Father”; the “Lord of Hosts” come down “with ten thousands of saints”; to Christendom Christ returned “in the glory of the Father,” to Shí‘ah Islám the return of the Imám Ḥusayn; to Sunní Islám the descent of the “Spirit of God” (Jesus Christ); to the Zoroastrians the promised Sháh-Bahrám; to the Hindus the reincarnation of Krishna; to the Buddhists the fifth Buddha. 

- Shoghi Effendi  (God Passes By, chapter 6)

Who Bahá’u’lláh is

He Who in such dramatic circumstances was made to sustain the overpowering weight of so glorious a Mission was none other than the One Whom posterity will acclaim, and Whom innumerable followers already recognize, as

• the Judge,
• the Lawgiver and Redeemer of all mankind, as
• the Organizer of the entire planet, as
• the Unifier of the children of men, as
• the Inaugurator of the long-awaited millennium, as
• the Originator of a new “Universal Cycle,” as
• the Establisher of the Most Great Peace, as
• the Fountain of the Most Great Justice, as
• the Proclaimer of the coming of age of the entire human race, as
• the Creator of a new World Order, and as
• the Inspirer and Founder of a world civilization.

- Shoghi Effendi  (God Passes By, chapter 6)