Bhagavad-Gita The Song Divine Chapter 9 (stanza 13-21)

On the other hand, Arjun, great souls who have adopted the divine nature, knowing Me as the prime source of all beings and the imperishable eternal, worship Me constantly with one-pointedness of mind ……………… (13)

Constantly chanting My names and glories and striving for my realization, and bowing again and again to me, those devotees of firm resolve, ever united with Me through meditation, worship Me with single-minded devotion. ……….. (14)

Others, who follow the path of Knowledge, betake themselves to Me through Yajna of knowledge, worshipping Me in My absolute, formless aspect as one with themselves; while still others worship Me in My Universal Form in many ways, taking Me to be diverse in manifold celestial forms. …………….. (15)

I am the Vedic ritual, I am the sacrifice, I am the offering to the departed; I am the herbage and food grains; I am the sacred mantra, I am the clarified  butter, I am the sacred fire, and I am verily the act of offering oblations into the fire. …………….. (16)

I am the sustainer and ruler of this universe, its father, mother and grandfather, the one worth knowing, the purifier, the sacred syllable OM, and the three Vedas - Rik, Yajus and Sama.  ……… (17)

I am the supreme goal, sustainer, lord, witness, abode, refuge, well-wisher seeking no return, origin and end, resting-place, store-house to which all beings return at the time of universal destruction, and the imperishable seed.  ……………. (18)

I radiate heat as the sun, and hold back as well as send forth showers, Arjun, I am immortality as well as death; even I am being and also non-being.  …….. (19)

Those who perform action with some interested motive as laid down in these three Vedas and drink the sap of the Soma plant, and have thus been purged of sin, worshipping Me through sacrifices, seek access to heaven; attaining Indra's paradise as the result of their virtuous deeds, they enjoy the celestial pleasures of gods in heaven.  ………… (20)

Having enjoyed the extensive heaven-world, they return to this world to mortals on the stock of their merits being exhausted. Thus devoted to the ritual with interested motive, recommended by the three Vedas as the means of attaining heavenly bliss, and seeking worldly enjoyments, they repeatedly come and go (i.e., ascend to heaven by virtue of their merits and return to earth when their fruit has been enjoyed) …… (21)