Yesod is dual, just like any Sephirah on the Tree of Life, which has its shadow within the abyss. If you wish to rise to the superior worlds, you must descend and face struggles against the mind, sorcery, defects, egos, and temptation, which occur when we work with the waters of sex reflected within the darkness of the infernal worlds.

These waters exist in a superior form above in the Tree of Life, but are polluted and defiled below Malkuth. Therefore, we must go down into the abyss in order to steal fire from the devil, to extract light from the chaos below, the murky, subconscious, unconscious, and infraconscious waters so that we can rise through death and resurrection.