Bhagavad Gita Chapter 9, Verse 31
क्षिप्रं भवति धर्मात्मा शश्वच्छान्तिं निगच्छति | कौन्तेय प्रतिजानीहि न मे भक्तः प्रणश्यति ||
kṣipraṁ bhavati dharmātmā śaśvac-chāntiṁ nigacchati kaunteya pratijānīhi na me bhaktaḥ praṇaśyati
He quickly becomes virtuous and attains everlasting peace. O Arjuna, declare it boldly that My devotee never perishes.
Krishna reveals the promise to devotees: 'Kṣipraṁ bhavati dharmātmā śaśvac-chāntiṁ nigacchati'—he quickly (kṣipram) becomes (bhavati) virtuous (dharmātmā) and attains (nigacchati) everlasting peace (śaśvac-chāntim). 'Kaunteya pratijānīhi na me bhaktaḥ praṇaśyati'—O Arjuna (kaunteya), declare boldly (pratijānīhi) that My (me) devotee (bhaktaḥ) never (na) perishes (praṇaśyati). This is the promise to devotees: they quickly become virtuous, they attain everlasting peace, and they never perish. This is the transformation: from bad conduct to virtue, from restlessness to peace, from perishing to eternal. This is the supremacy of devotion: it transforms quickly, it brings peace, it ensures you never perish. This is why devotion is superior: it brings quick transformation, lasting peace, and eternal existence.