Guna: literally, "a strand of a cord or rope." The three gunas of Prakriti are defined as three intertwined strands of the binding cord of Nature. Through this medium Prakriti holds in bondage all embodied beings.
The three attributes of Nature:
sattva - good
tamas - evil
rajas - activity
the positive attribute, influences toward good, truth, purity, spirituality, wisdom.
evil, the negative attribute, influences toward darkness or evil, untruth, inertia, ignorance and delusion.
the neutral attribute, is the activating quality: working on sattva to suppress tamas or on tamas to suppress sattva, it creates constant activity and motion. Greed, restlessnes and desire.
Spirit employs the three modes of Nature to appear as
(1) the Creator or Brahma (rajas, activity),
(2) the Preserver or Vishnu (sattva, the nourishing quality), and
(3) the Destroyer or Shiva (tamas, dissolution).