The fourteenth chapter of the Bhagavad Gita discusses
sattva, rajas, and tamas, the three constituents (gunas) of Prakriti, or
Nature. By Nature is meant everything other than the Spirit. Thus our mind,
sense organs, and body are also part of Nature, or are products of sattva,
rajas, and tamas.
These three gunas inhere in different proportions in an individual, one predominating over the other two. Spiritual evolution involves freeing ourselves of attachment to body, mind, and senses. It is a journey from tamas to sattva.
Tamas stands for inertness and dullness, and rajas for
activity mixed with passion, desire, restlessness, and attachment to action and
its result. Sattva signifies calmness in the midst of activity.
The spiritual seeker has to get rid of tamas through
activity, rajas, remaining free at the same time of the negative aspects of
rajas like passion, desire, and attachment. This is called karma-yoga, or
performing work as worship. Such selfless action leads the seeker gradually to
sattva, which is the penultimate step to Self-realization.
An important point to note is that our acts of devotion,
such as japa, prayer, worship, and meditation are also activities that help in
the manifestation of sattva. Self-effort is thus indispensable for spiritual
evolution.
Notes taken from - Self-Effort and Self-Surrender Teachings
by Swami Yuktatmananda