Randolph's most consequential and most controversial teaching concerned sex magic, the idea that the energies of sexual union, rightly directed by the will and imagination at the moment of climax, could be used to work magical effect and attain spiritual illumination. He appears to be the figure who introduced a systematic doctrine of this kind into the modern Western tradition, presenting it in works such as Eulis! and in privately circulated manuscripts. The teaching was scandalous in Victorian America and contributed to legal trouble and to his marginalization.
He founded a series of initiatory bodies devoted to his interpretation of Rosicrucianism, including the Brotherhood of Eulis and organizations that fed into the later Fraternitas Rosae Crucis, presenting himself as the head of a Rosicrucian order and grounding his authority in his travels in the East rather than in European lodge lineages.
His influence far outran his fame. His sexual-magical teachings passed, in altered form, into the German occultist Theodor Reuss and the Ordo Templi Orientis, and so into the work of Aleister Crowley, becoming a central thread of twentieth-century magic. That much of this influence was unacknowledged, and that its Black American originator was long written out of the story, has made the recovery of Randolph a significant chapter in the modern history of Western esotericism, the context in which this atlas records him.