Why we bathe in Ganga Krishna or Kaveri River

All creatures, born from you, move round upon you. You carry all that has two legs, three, or four. To you, O Earth, belong the five human races, those mortals upon whom the rising sun sheds the immortal splendour of his rays.

May the creatures of earth, united together, let flow for me the honey of speech! Grant to me this boon, O Earth.

Mother of plants and begetter of all things, firm far-flung Earth, sustained by Heavenly Law, kindly and pleasant is she. May we ever dwell on her bosom, passing to and fro! As a vast abode, Earth, you have become great. Great is your movement, great your trembling, your quaking. The Lord all-powerful ceaselessly protects you. O Earth, grant us to shine like burnished gold, and let no enemy ever wish us ill!

Agni resides on earth, within the plants. The Waters contain Agni; in the stones is he. Agni abides deep in the hearts of Men. In cattle and in horses there are Agnis. [Atharva Veda XII, 1, 15-19]

Why we bathe in Ganga Krishna or Kaveri River

Within the Waters, Soma has told me, remedies exist of every sort and Agni who brings blessing to all. O Waters, stored with healing balm through which my body safe will be, come, that I long may see the sun. Whatever sin is found in me, whatever wrong I may have done, if I have lied or falsely sworn, Waters, remove it far from me. Now I have come to seek the Waters. Now we merge, mingling with the sap. Come to me, Agni, rich in milk! Come and endow me with your splendour!  [Rig Veda X, 9, 6-9]

The mighty burden of the mountains bulk rests, Earth, upon your shoulders; rich in torrents, you germinate the seed with quickening power.[Rig Veda V, 84, 1]. The Nidhana is the cessation. It rains for him whenever he desires and he brings rain for others even when there is no rain who, knowing this, meditates on the fivefold Saman as rain.[Sama Veda, Chhandigya Upanishad II,III - Meditation on the Fivefold Saman as Rain, 1-2]. One should meditate on the fivefold Saman in all the waters. When the clouds gather, that is the syllable Him; when it rains, that the Prastava; the rivers which flow to the east, these are the Udgitha; the rivers which flow to the west, these are the Pratihara; the ocean is Nidhana. He does not die in water and he becomes rich in water who, knowing this, meditates on the fivefold Saman in all the waters.[Sama Veda, Chhandigya Upanishad II,IV - Meditation on the Fivefold Saman as Water, 1-2] One should meditate on the fivefold Saman as the seasons. The syllable Him is the spring, the Prastava the summer, the Udgitha the rainy season, the Pratihara the autumn, the Nidhana the winter. The seasons belong to him and he becomes rich in seasons who, knowing this, meditates on the fivefold Saman as the seasons. [Sama Veda, Chhandigya Upanishad II,V - Meditation on the Fivefold Saman as the Seasons, 1- 2]