Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 13


भस्मीभूताङ्गसङ्गेन स्वर्याता: सगरात्मजा: ।किं पुन: श्रद्धया देवीं सेवन्ते ये धृतव्रता: ॥ १३ ॥


bhasmībhūtāṅga-saṅgenasvar yātāḥ sagarātmajāḥkiṁ punaḥ śraddhayā devīṁsevante ye dhṛta-vratāḥ


Simply by having water from the Ganges come in contact with the ashes of their burnt bodies, the sons of Sagara Mahārāja were elevated to the heavenly planets. Therefore, what is to be said of a devotee who worships mother Ganges faithfully with a determined vow? One can only imagine the benefit that accrues to such a devotee.