Rajas is passion, motion. It causes attachment and thirst for mundane life. Inertia is darkness. It causes heedlessness, laziness, indolence, and sloth. Sattva is purity, harmony. It produces peace and bliss
From Amrita Gita by Swami Sivananda, copyright The Divine Life Society. Swami Sivananda was a self-realized Master and a very practical Guru. Following His teachings can lead you to the Absolute.