Essence, Qi, and Spirit are the three vital signs of a cultivator's life.
"Essence" refers to the physical body, "Qi" refers to the True Qi cultivated within the Qi Sea, and "Spirit" is the most special, referring to the Divine Sense and Divine Soul hidden within the mind!
The physical body can always be strengthened by ordinary people; while True Qi can only be cultivated by those who have opened up the Qi Sea; as for the Divine Soul, it is even more special, only those with profound cultivation or who have come into contact with special techniques may strengthen the Divine Soul!