Thread, or, more specifically, the Thread of Life is a spiritual symbol that has been around for a long time.  It is said to symbolize destiny, fate unity and continuity.  It symbolizes the invisible (to most of us) spiritual thread that links all of us together on a spirit level.  When the thread is depicted going through a pearl, gem, or stone, it symbolizes a cycle of some kind, usually, a spiritual cycle.  
    In Greek mythology, the Moirae (fates) controlled the thread of life from the moment of birth.  The Egyptians called them Hathors. The Babylonian goddess Ishtar  was said to spin the thread of life.  Some Christian artists adopted this idea and depicted Mary at a spinning wheel spinning the thread of life.
A verse from a Native American poem titled "The Deformed Artist" found in the ebook "Indian Legends and Other Poems", by Mary Gardiner Horsford:



"The spectral form of Death is nigh,
       The thread of life is spun:
     Ave Maria! I have looked
       Upon my latest sun.
     And yet 't is not with pale disease
       This frame is worn away;
     Nor yet—nor yet with length of years;—
       A child but yesterday,"

    In modern times, the legend of the thread of life now has scientific backing from the world of quantum physics.  In quantum physics, the solid-looking universe is actually just an intricate matrix or tapestry woven in beams of light ( some say it's just one beam) and the beams carry information.  Where the beams cross, they exchange information so eventually each beam has all the information in the universe in it.
    Members of  the International Community of Christ  wear a symbolic thread of life around our waist with eight gems or crystals attached to it representing the eight energy centers (chakras).