Gleanings from the Writings of Bahá’u’lláh

They that have joined partners with Him, however, are unaware of such a revelation, and are deprived of the Faith through which they can draw near unto, and be united with, Him. Witness how the divers peoples and kindreds of the earth bear witness to His unity, and recognize His oneness. But for the sign of the Unity of God within them, they would have never acknowledged the truth of the words, “There is none other God but God.” And yet, consider how grievously they have erred, and strayed from His path. Inasmuch as they have failed to recognize the Sovereign Revealer, they have ceased to be reckoned among those who may be regarded as true believers in the Unity of God.

This sign of the revelation of the Divine Being in them that have joined partners with Him may, in a sense, be regarded as a reflection of the glory with which the faithful are illumined. None, however, can comprehend this truth save men endued with understanding. They that have truly recognized the Unity of God should be regarded as the primary manifestations of this Name. It is they who have quaffed the wine of Divine Unity from the cup which the hand of God hath proffered unto them, and who have turned their faces towards Him. How vast the distance that separateth these sanctified beings from those men that are so far away from God!...