Religious people believe the Karma theory is a universal theory. The Karma theory is a religious and yogic fable.+

From the Advaitic perspective, the Karma theory has no value.  Karma is based on birth entity whereas the Soul, the unborn eternal has no karma. 

Sage Sankara says clearly, the universe is not real. He says that Brahman and Atman are one. The Ultimate and the Absolute Truth is the 'Self', which is one though appearing as many in different individuals. The individual has no reality. Only the ‘‘Self’’ is Real; the rest, mental and physical are but passing appearances, then it indicates the form (waking) is unreal the formless is real (Soul). Therefore, only Atman is real because there is no second thing other than Atman.

Sage Sankara also clearly mentions that:- The path of religion, the theory of Karma, the path of yoga, and the path of wisdom were intended for different classes of people. The wisdom is for the advanced seekers of truth. It deals with the nature of the ultimate truth or the ultimate Reality. It is meant for superior aspirants who have an inner urge to know the truth and it is not for those who are immersed in earthly desires.

Remember:~

Karma (Action) will not dispel ignorance itself. Karma itself is based on ignorance Only Self-Knowledge or Brahma Gnana or Atma Gnana will destroy ignorance.

Sage Goudpada says: ~ The merciful Veda teaches Karma and Upasana to people of lower and middling intellect while Jnana is taught to those of higher intellect.

It means the people who follow religion and worship of Gurus and conceptual God and believe in karma theory are lower and middling intellect. In this modern world, people are sharp enough to understand and assimilate the ultimate truth or Brahman or God in truth. Thus, it is high time to discard the lower knowledge and move ahead to realize the ultimate truth, which is Brahman or God in truth.

Religious people believe the Karma theory is a universal theory. The Karma theory is a religious and yogic fable.

The Karma theory is a universal theory for those who believe the dualistic illusion as a reality. Karma is a reality only for those who believe the false self (ego or you) as the real 'Self' and the false experience (waking or universe) as a reality.

The Karma theory is a reality for those who believe the experience, the form, time, and space as a reality. Karma theory is a reality for those who believe in an individualized God. The Karma theory is a reality for those who believe in the experience of birth, life, death, and rebirth, and the world as a reality.

The Karma performed in the dream becomes unreal when the waking takes place. Similarly, the waking karma becomes unreal when wisdom dawns. The karma theory is a universal theory when karma is limited to waking experience alone.

The wisdom dawns when you (doer of Karma) realize you are not the 'Self, but the 'Self' is the formless Soul. Thus, all theories based on you (form) are a falsehood because, the Soul, the innermost 'Self' is ever formless, timeless, and spaceless existence.

If the 'Self' is not the waking entity but the 'Self' is the formless Soul then how anyone can accept the theory of Karma, which is based on false 'Self' within the false experience.

Thus, whatever theories are based on the false self (waking entity or ego) and false experience (waking or the world) is bound to be a falsehood.

Karma is a reality only for those who are stuck with the reality of the practical life within the practical world because they have accepted the world in which they exist as a reality.

Without knowing what witnesses the coming and going, of the three states how can one say the Karma theory is a universal theory when karma is limited to waking experience alone.

If the 'Self' is not you (waking entity) but the 'Self' is formless Soul then how anyone can accept the theory of Karma, which is based on false self within the false experience.

Thus, whatever theories are based on the false 'Self' (waking entity or you) and false experience (waking or the world) is bound to be a falsehood.

Karma is a reality only for those who are stuck with the reality of the practical life within the practical world because they have accepted the world as reality.

What is the doer, what is the enjoyer, what is a cessation of thought and rising of thought, what is immediate perception and its result, to the Soul, the  'Self', the ever impersonal?

What is the world, what is meant by the aspirant for liberation; what is the contemplative man and what is a man of knowledge; what is bondage and what is liberation to the 'Self',  which is ever formless, timeless, and spaceless existence.

What is Prarabdha Karmas, what is even liberation in life, and what is that and where is liberation at death for the Soul, the 'Self', which is ever attributeless?

The nearest state to understand the Soul by itself is to eliminate the whole waking experience, as in deep sleep. Once this is grasped one has to understand that the three states are Soul, which is present in the form of consciousness, that Soul or consciousness is the 'Self'.

Whether the Karma theory existed prior to Buddhism is not the question. Karma theory is based on form, time, and space whereas the ultimate truth or Brahman is based on formless, timeless, and spaceless existence. Thus, one has to decide whether the 'Self' is the form or 'Self' is nondual. If 'Self' is the form then Karma theory has value but if the 'Self' is formless then the karma theory has no value.

Deeper-self’-search reveals the fact that the Karma theory is meant for those who are immersed in worldly life thinking of the individual life within the particle world as a reality. In the Atmic path, the Karma theory becomes a great obstacle in realizing the truth. : ~ Santthosh Kumaar