Sage Sankara says liberation consists in realizing the true nature of the Self as the eternal, non-dual reality. And so it cannot result from karma.+

Religious orthodox people think that they have accomplished life's purpose by indulging in rituals and sacrifices prescribed by the scriptures and advice of their Gurus but these performers of rituals and sacrifices do not know the Truth owing to their attachment they remain in ignorance.

Sage Sankara says liberation consists in realizing the true nature of the Self as the eternal, non-dual reality. And so it cannot result from karma. It is a matter of common knowledge that anything which is produced by action is impermanent (anitya). If liberation were the result of karma then it would be impermanent and such a state is not really desirable~ -Sage  Sankara in his Intro. To Taitt Up

Even Sage Sankara appears and tells the orthodox people the path of orthodoxy is the path of ignorance they will not be able to drop their inherited samskara or conditioning, which they think is the only way to reach heaven and reap a happy life in the next life.

As regards the rituals, Sage Sankara says, that the person who performs rituals and aspires for rewards will view himself in terms of the caste into which he is born, his age, the stage of his life, his standing in society, etc. In addition, he is required to perform rituals all through his life. However, the Self has none of those attributes or tags. Hence, the person who superimposes all those attributes on the changeless, eternal Self and identifies the ‘Self’  with the body is confusing one for the other; and is, therefore, an ignorant person. The scriptures dealing with rituals, rewards, etc. are therefore addressed to an ignorant person.-  (11- Adhyasa Bhashya)

First Mundaka - Chapter 2 (10) - Ignorant fools, regarding sacrifices and humanitarian works as the highest, do not know any higher good. Having enjoyed their reward on the heights of heaven, gained by good works, they still remain in ignorance of the Atman the real God.

As a person, one performs rituals throughout his life.  The person who performs rituals and aspires for rewards will view the world in which he exists as a reality. However, the Soul, the Self unborn eternal hidden by the world in which he exists.  From the standpoint of the Soul, the world in which he exists is merely an illusion.

The scriptures dealing with rituals, rewards, etc. are therefore addressed to an ignorant person.

First Mundaka - Chapter 2 (9) - Children, immersed in ignorance in various ways, flatter themselves, saying: We have accomplished life's purpose. Because these performers of karma do not know the Truth owing to their attachment, they fall from heaven, misery-stricken, when the fruit of their work is exhausted.

First Mundaka - Chapter 2 (8) - Fools, dwelling in darkness, but wise in their own conceit and puffed up with vain scholarship, wander about, being afflicted by many ills, like blind men led by the blind.

Ish Upanishad declares: - Those people who have neglected the attainment of Self-knowledge and have thus committed suicide. 10/11/12

The religious orthodox people who have neglected the attainment of Self-knowledge and have thus committed suicide, as it were, are doomed to enter those worlds after death.

This is a condemnation of people who do not try to attain Self-knowledge. They are, in a real sense, committing suicide, for what can be worse than being a slave to sense enjoyment, completely oblivious of the real purpose of life, which is to be one’s, own master?

Ish Upanishads:-

MANTRA 10

Vidya and Avidya both are hindrances to Self-knowledge, but Vidya is even worse than Avidya. The word Vidya is used here in a special sense; here it means worshipping Gods and Goddesses. By worshipping Gods and Goddesses you will go after death to the world of Gods and Goddesses. But will that help you? The time you spend there is wasted because if you were not there you could have spent that time moving forward towards Self-knowledge, which is your goal. In the world of Gods and Goddesses, you cannot do that, and thus you go deeper and deeper into darkness.

Avidya is Karma and therefore a hindrance. You perform Avidya - i.e., you perform Agnihotra and other sacrifices. This is a roundabout way of purifying the mind, and it is also groping in the dark. But it may not have as heavy a toll on your time and energy as the other.

Ishopanishad: ~ “They are steeped in ignorance and sunk into the greatest depth of misery who worships the matter, instead of the All-Pervading God and those who worship things born of matter like trees, animals, man, etc. are sunk deeper in misery." : ~ Santthosh Kumaar