Link to purport by A C Bhaktivedanta Swami Srila Prabhupada

Transcript of Bhakti-Shastri class on this verse by Chaitanya Charan

Bg 16.22

etair vimuktaḥ kaunteya
tamo-dvārais tribhir naraḥ
ācaraty ātmanaḥ śreyas
tato yāti parāṁ gatim

Synonyms: 

etaiḥ — from these; vimuktaḥ — being liberated; kaunteya — O son of Kuntī; tamaḥ–dvāraiḥ — from the gates of ignorance; tribhiḥ — of three kinds; naraḥ — a person; ācarati — performs; ātmanaḥ — for the self; śreyaḥ — benediction; tataḥ — thereafter; yāti — he goes; parām — to the supreme; gatim — destination.

Translation: 

The man who has escaped these three gates of hell, O son of Kuntī, performs acts conducive to self-realization and thus gradually attains the supreme destination.

etair vimuktaḥ, after being independent of this kaunteya, 

tamo-dvārais tribhir naraḥ, the doors to darkness to ignorance 

ācaraty, that person acts in what way? ātmanaḥ śreyas, for the well-being of one’s soul

And thereafter tato yāti parāṁ gatim, and thus can attain the Supreme destination. 

So for us on spiritual path often we are our greatest enemy means we often acts in such a way which is self-defeating and self-destructing so that can be seen at a very gross level when people smoke or drink, at the grossest level people commit suicide. By lust anger and greed also we are harming us spiritually and materially. 

Krishna has used tyajet in previous verse and here vimuktaḥ, give them up, which means it is possible to become free from these. It is like a ghost haunting a person, the person can become free from it. When one become free from them one can think clearly. 

ācaraty ātmanaḥ śreyas, when one become free from it one can act in pursuance of self-interest and he can perceive what is good for him. 

tato yāti parāṁ gatim, one will attain Supreme destination. 

Purport: Sirala Prabhupada talked about Varanshram system… There are different rules and regulations for different castes or divisions of society, and if a person is able to follow them, he will be automatically raised to the highest platform of spiritual realization. Then he can have liberation without a doubt.

End of transcription.