Chapter 17 · verse 28 · gita.yoga.org

Bhagavad Gita 17.28

अश्रद्धया हुतं दत्तं तपस्तप्तं कृतं च यत्।असदित्युच्यते पार्थ न च तत्प्रेत्य नो इह

Whatever is sacrificed, given, or performed, and whatever austerity is practiced without faith, it is called 'Asat', O Arjuna; it is of no value here or hereafter (after death).