Here is the verse and purport of Gita 9.21
The translation is: When they have thus enjoyed vast heavenly sense pleasure and the results of their pious activities are exhausted, they return to this mortal planet again. Thus those who seek sense enjoyment by adhering to the principles of the three Vedas achieve only repeated birth and death.
This text is the end of what felt to me like a long section (texts 16-20) where Kṛṣṇa is explaining that there are some people who are neither good (mahatma) nor bad (duratma) but are somewhere in between because they do “spiritual” and “religious” things like good people but they, like bad people, are still averse to directly embracing Godhead as the Supreme Personal Enjoyer.
Krishna’s main point in this section is that it is shallow to do religion and spirituality without embracing the Supreme Personality of Godhead directly. It is “shallow” because it does not appreciate that the source of value in all of the aspects of religion and spirituality is the Supreme Personality of Godhead. Divorced from the Supreme Personality, even religion and spirituality become useless.
Here is a summary of the 9th Chapter of Gita so far:
Kṛṣṇa, “You are a very good person, Arjuna, so I will tell you an amazing secret. Bad people would not understand what I will say.”
Arjuna, “Who is a bad person?”
Kṛṣṇa, “One who is unwilling to accept that the Supreme Personality of Godhead cannot be ignored or dismissed, and who therefore offers no love to me.”
Arjuna, “Who is a good person?”
Kṛṣṇa, “One who embrace me with pure love, and therefore always desires to sing my names, etc.”
Arjuna, “What about people who are a little bit good and a little bit bad?”
Kṛṣṇa, “Yes. They are the people who do spiritual and religious things, but are forgetful that it is all supposed to be a means of embracing me with pure love.”
Arjuna, “Can you give some examples?”
Kṛṣṇa, “Sure! Here are four examples: (1) People doing rituals forgetting that every element of the ritual is me and therefore meant to embrace me. (2) People cultivating knowledge but forgetting that every element of philosophy and science is me, and therefore meant to increase their love for me. (3) People doing good, but forgetting that the whole purpose and ability to do good is to please me, who am myself everything good and everything good that can be done. (4) People appreciating nature but forgetting that I am behind everything they appreciate.”
Arjuna, “What is the result of being only half-good like these four?”
Kṛṣṇa answers in texts 20-21, “People who worship me indirectly get some indirectly good result. They get freed from bad karma and therefore get born into heaven and enjoy paradise.”
Sounds great, but then Kṛṣṇa explains text 21: “They remain in paradise for as long as their good karma warrants. Then they are again born in the mortal world. So in the end, they don’t really get anything that lasts. All they get is more birth and death.”
Now let’s carry this home and make it real for you and me.
What will anyone get by being a good mataji? By being a perfect father, mother, or child? By being a perfect brahmacari? What will I get by renouncing everything and becoming a sanyassi? Or by making a million dollars and donating it to temples and spiritual teachers?
What will I get by following every rule I am told to follow? What if I follow all 64 angas of Vaidhi-Sadhana bhakti?? What if I dabble in raganuga sadhana bhakti and try to follow the rules of that path, what will it get me???
What will I get by putting on a sari or dhoti, tilok and tulsi beads around my neck? What will I get from writing this!?!?!?? What will you get by dutifully finishing to read it!!?!?!?? What will I get by studying Bhagavada-Gita, Srimad Bhagavatam, and on and on up to Govinda-Lilamrta, Ananda Vrindavana Campu, and so on!?
My friends, what will I get from all this?
What about my “Schnick Schick mahamantra…” What will I get in return for chanting it 1, 2, 4, 8, or 16×108 times, or even 64×108, or even 128×108 daily? What will I get by dancing in the middle of a wonderful Śrī Hari-nama-sankirtana in the holy dhama of Vrindavana or Mayapura???
The answer is in texts 20-21: If my heart is not focused on adoring Kṛṣṇa through any of these activities I will at best become a “good person” and go spend some time in heaven, where all the really good parties are, in my next life.
But what if my heart is focused directly on pleasing Kṛṣṇa??? Oh, my! That is the secret that Kṛṣṇa opened up the chapter saying he would tell us!!! The answer is coming up in the remainder of the chapter!
Suffice to say that nothing I can do or say will ever bring me any permanent joy unless and until my heart shelters the single, simple, lovely, solitary, beautiful desire to purely love the personality who is the soul of my very own soul: Śrī Kṛṣṇa. And, conversely, as soon as that one simple desire appears like a blossoming lotus in the pond of my soul – at that moment anything and everything I do and say will become an eternal joy!
For detail lovers, here is an itemized list of the things Kṛṣṇa mentions in texts 16-19:
In text 16 Kṛṣṇa talks about the items of normal religion (Actual ritualistic priests might be able to explain the items in better detail than I.):
- Kratu – Religious rituals / sacrifices to attain heaven
- Yajna – A part of the religious ritual: the fire consuming the items sacrificed
- Svadha – The procedure of placing the sacrificial items in the fire
- Aushada – The sacrificial offering (a kind of intoxicant / medicine / drug to benefit the gods)
- Mantra – The words of power incanted by the priest to infuse the ritual with spiritual potency
- Ajyam – The ghee-oil burning in the sacrificial fire
- Agni – The flames themselves
- Huta – The process of pouring ghee-oil onto the fire.
In text 17 Kṛṣṇa talks about the parts of sankhya philosophy (again, someone who specializes in Sankhya could surely explain the details better. To some extent the first four items have a double meaning indicating the religion of ancestor worship):
- Pita – The “father” who gives the seed of all the universes (mahat-tattva)
- Mata – The “mother” who takes the seed and develops it in her womb (prakriti)
- Data – The “nurse” who nourishes the universe, giving it power
- Pita-maha – The “grandfather” Lord Brahma, who gives the empowered universe elements their shape in creation.
- Vedyam – the objects of the senses and the mind thus created
- Pavitram – the process of being purified of ego so that one can correctly understand philosophy
- Om kara – The essential syllable of recorded philosophy and religion
- Rk, Sama, Yajuh – The main books in which religion and philosophy is recorded
In text 18 Kṛṣṇa speaks of items of religion as karma-yoga:
- Gati – The goal of right behavior
- Bharta – The sustainer of the goal
- Prabhu – The master who owns and bestows the goal
- Saakshii – The witness of the right behavior
- Nivaasa – The safe haven of good people
- Saranam – The protector from wrong behavior
- Suhrit – The well meaning friend who encourages right behavior
- Nidhanam – The treasures to be rightly shared, and the treasure to be attained by right behavior
- Bijam Avyayam – The moral ideas to act rightly without being swayed
In Text 19 Kṛṣṇa talks about nature-worship religion:
- Tapami – Warmth (summer, the sun, etc.)
- Varsham – Rain
- Nigrihnami utsrijami – The powers of nature which cause warmth and rain to ebb and flow.
- Amritam – Lifeforce (another meaning: Liberation)
- Mrityu – The power of death (another meaning: bondage)
- Sat – What is real (consciousness) – another meaning: the thoughts and emotions.
- Asat – What is not real (temporary material forms) – another meaning: the physical.
These four texts – 16, 17, 18, and 19 – are a unified group in which Kṛṣṇa expands on a single theme that he introduced at the end of text 15. That theme is how people can engage in aspects of religion and philosophy without realizing the Supreme Personality of Godhead to be the reason any of those things are important in the first place.