Bhagavad Gita 9.31

He will soon attain spirituality and eternal peace. O Arjuna! Believe me, my devotee is never lost.

क्षिप्रं भवति धर्मात्मा शश्वच्छान्तिं निगच्छति।
कौन्तेय प्रतिजानीहि न मे भक्तः प्रणश्यति॥

kṣipraṃ bhavati dharmātmā śaśvacchāntiṃ nigacchati|
kaunteya pratijānīhi na me bhaktaḥ praṇaśyati||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).