God will verily inspire them with whatsoever He willeth

It is now evident and firmly established that Bahá’u’lláh’s Covenant provides for two authoritative centres. The first is the Book: the Revelation of Bahá’u’lláh, along with the body of works of ‘Abdu’l-Bahá and Shoghi Effendi that constitute authoritative interpretation and explication of the Creative Word. With the passing of Shoghi Effendi, more than a century of the extension of that authoritative centre came to a close.

The second authoritative centre is the Universal House of Justice, which, as the Sacred Writings affirm, is under the care and unerring guidance of Bahá’u’lláh and the Báb. “Let it not be imagined that the House of Justice will take any decision according to its own concepts and opinions”, ‘Abdu’l-Bahá explains. “God forbid! The Supreme House of Justice will take decisions and establish laws through the inspiration and confirmation of the Holy Spirit, because it is in the safekeeping and under the shelter and protection of the Ancient Beauty”. “God will verily inspire them with whatsoever He willeth,” Bahá’u’lláh proclaims. “They, and not the body of those who either directly or indirectly elect them,” Shoghi Effendi states, “have thus been made the recipients of the divine guidance which is at once the life-blood and ultimate safeguard of this Revelation.

(The Nine Year Plan: 2022–2031, Messages of the Universal House of Justice, 180 B.E. Edition, Paragraph 22 and 23)