Bhagavad Gita 9.3
अश्रद्दधानाः पुरुषा धर्मस्यास्य परन्तप। अप्राप्य मां निवर्तन्ते मृत्युसंसारवर्त्मनि।।9.3।।
aśraddadhānāḥ puruṣā dharmasyāsya parantapa| aprāpya māṃ nivartante mṛtyusaṃsāravartmani||9.3||
ashraddadhanah purusha dharmasyasya parantapa aprapya mam nivartante mrityusamsaravartmani9.3
Meaning
Those who have no faith in this dharma do not attain Krishna; they return to the path of death and transmigration in the material world. Faith is essential for spiritual progress.
हे परन्तप! इस धर्म में श्रद्धारहित पुरुष मुझे प्राप्त न होकर मृत्युरूपी संसार में रहते हैं।
This is verse 3 of 34 in Chapter 9 (Raja Vidya Raja Guhya Yoga) of the Bhagavad Gita.