Bhagavad Gita Chapter 5, Verse 25

लभन्ते ब्रह्मनिर्वाणमृषयः क्षीणकल्मषाः | छिन्नद्वैधा यतात्मानः सर्वभूतहिते रताः ||

labhante brahma-nirvāṇam ṛṣayaḥ kṣīṇa-kalmaṣāḥ chinnadvaidhā yatātmānaḥ sarva-bhūta-hite ratāḥ

Sages whose sins are destroyed, whose dualities are cut off, who have controlled the self, and who are engaged in the welfare of all beings, attain the nirvana of Brahman.

Krishna describes the sages who attain liberation: those whose sins are destroyed (kṣīṇa-kalmaṣāḥ), whose dualities are cut off (chinnadvaidhāḥ), who have controlled the self (yatātmānaḥ), and who are engaged (ratāḥ) in the welfare of all beings (sarva-bhūta-hite). They attain (labhante) the nirvana of Brahman (brahma-nirvāṇam). This means the sages who attain liberation are those who have destroyed sins through knowledge, cut off dualities through equanimity, controlled the self through discipline, and are engaged in the welfare of all beings through selfless action. This is the complete picture of karma yoga—purification, equanimity, self-control, and selfless service. All four aspects are necessary for liberation.