Introduction to Samkhya:-
Samkhya or Sankhya is one of the sixth orthodox schools of Hindu Philosophy which is related to yoga. Philosophy of yoga is an enumerations philosophy whose epistemology accepts three of Six Brahmanas (Proofs) as only reliable means of Gaining knowledge. These Includes :
1) Pratakshya (Physical prove with five sense)
2) Anumana ( Inference)
3) Sabda (Word Testimony from a reliable scholar/Source)
In Short, Samkhya state that:-
“This Universe has two reality – One is Purusa (Pure consciousness) and Second is Prakriti (Matter). Jiva ( a living being) is that state in which purusa bounded with Prakriti to perform the physical action (Karma). This fusion of purusa and Prakriti is the emergence of Buddhi (Intellect) and Ahankara (Ego Consciousness). It also describes that Jiva with Buddhi has three basic Guna – Satvik, Rajas and Tamas.
“Sattva is the quality of balance, harmony, goodness, purity, universalizing, holistic, constructive, creative, building, positive, peaceful, virtuous.
Rajas are the quality of passion, activity, neither good nor bad and sometimes either, self-centeredness, egoistic, individualizing, driven, moving, dynamic.
Tamas is the quality of imbalance, disorder, chaos, anxiety, impure, destructive, delusion, negative, dull or inactive, apathy, inertia or lethargy, violent, vicious, ignorant”
Bhagwat Gita on Guna:
Action that is virtuous, thought through, free from attachment, and without craving for results is considered Sattvic; Action that is driven purely by craving for pleasure, selfishness and much effort is Rajasic; Action that is undertaken because of delusion, disregarding consequences, without considering loss or injury to others or self, is called Tamasic.
— Bhagavad Gita, Chapter 18, verses 23–25 
During the state of imbalance, one more constitute overwhelmed the others and created the different form of bondage, particular for the mind. The end of imbalance of Bondage is known as Liberation.
Samkhya Consider Vedas as a reliable source of Knowledge and denies that everything happened according to Iswara.
Bhagavad Gita, In chapters 14, 17, and 18, Krishna portrays the gunas in marvellous detail. He begins (in verse 14.5) by describing the power of the gunas to “bind the immutable embodied One.” He goes on to provide an account of the nature of each guna. Later (in verse 18.40), Krishna dramatically summarizes the scope of the gunas’ activities:
There is nothing on the earth, in heaven, or even among the gods, that is free from this Prakriti-born gunas.- Chapter 18 Verse 40.
These gunas in different ratios have created the characters of human which can be modified by karma.
These three gunas are already explained above has real implication in life. For understanding the difference between Satvik and Rajsik we need to understand by example:-
Anything in a Natural state in Prakriti without altered is Satvik – Like Tomato grows in nature but when we made it tomato sauce its become Rajsik because it has been altered from its original taste. These very Satvik Gunas are natural gunas without altered the reality of Prakriti.
The Difference between Tamas and Rajas:-
If “Satvik” is “Need” than “Rajas” is “attachment” and “Tamas” is “obsession”. Example, When you are sick and need rest is Satvik need, but if you sleep for pleasure is Rajsik but when you sleep for non-action or laziness its Tamsik in nature.
I would like to further extend to How Dharma and religion are affected by these gunas.
#Satvik- Any worship to natural forms and praise for the thing which is directly responsible for life on earth is the example of Sattva. “Dharma” in its true definition is only “Righteous living with nature”. Dharma state that ” the eternal law of the cosmos, inherent in the very nature of things ”.
#Rajsik- Any worship which involves materialistic and Organised pleasure after altering the natural worship is Rajsik in nature. Although it’s not right to say its good and bad. But Rajsik nature of religion is less flexible and inherited “Dharma with Matrialstic pleasure”. All Religion, for example- Christianity is talked about Love and sacrifice in large context but never denied materialism. The Church truly believe in materialistic power and pleasure in name of God. Rajsik nature of Religion is impulsive, self-centeredness, egoistic, individualizing, driven, moving, dynamic.
#Tamsik- The other word used for Tamas is “Steady” . The very religion under Tamas is Strong but steady. it’s belief in complete submission to “materialistic God”. This is being the steady and obsession form of Rajsik Religion. It’s belief in imbalance of power, disorder of societies, chaos amongst unbelievers, anxiety for believers, See others as impure, destructive in nature, delusion in rationalisation, negative in reform, dull or inactive in rationalisation, violent in core nature and ignorant of the facts.
In the current world, we are facing Rajsik Religion where human race carving to become the materialistic cult. This Rajsik Religion is encountering with Tamsik religion and Satvik Dharma in its low position for now. The future of human race depends on how we perceive to subjugate the Tamsik religion and overcome Rajsik Religion to attend Satvik Dharma. The rise of Satvik Dharma is need of time with proper reformation and if needed proper reincarnation.
Although Law of Nature defines that “Things which was rise are subject to fall, and things which fall are subject to rising. This inevitable cycle of nature. Call it Yin Yang or Call it Cycle of nature.”
PS: Theory of Gunas suggest that everything around us have these three gunas in different ratios for creating the basic nature of realities. The very human being has these nature and leads its life according to these nature. Moreover, these nature can be controlled by Karma and Dharma.
1) Wikipedia – https://en.wikipedia.org/wiki/Samkhya
2) Wikipedia- https://en.wikipedia.org/wiki/Gu%E1%B…
3) Bhagwat Gita- http://www.bhagavad-gita.org/Gita/ver…
4) Three Gunas – https://yogainternational.com/article…
5) Defination of Dharma in Google.