As long as people have been marking and modifying their physical appearance, there has been a strong spiritual element to the practice of body art and body modification.
Even before the rise of organized religions, Judaism, Christianity and Islam in the West and Buddhism & Hinduism in the East, with their widely recognized symbols of religious faith and devotion, tattoos often clearly were intended to serve a purpose beyond simple expressions of decoration and identification.
Many early tattoos clearly had a cosmic connection and wove early man into the fabric of the larger universe.