The poem was not purely literary. Ritual instructions from the Seleucid period describe the akitu, the Babylonian new year festival held in the month of Nisan, and record that Enuma Elish was recited in full by the high priest before the statue of Marduk on the fourth day. That places the text inside an annual civic ritual in which the king was ceremonially humiliated before Marduk and then reconfirmed, and it suggests the poem functioned as a periodic re-enactment of the order it describes. How far back the practice extends before the Seleucid tablets that describe it is uncertain.
The modern reception began with George Smith, a former banknote engraver turned Assyriologist at the British Museum, who announced a Babylonian flood account in 1872 and published creation fragments shortly afterwards, gathering the material in The Chaldean Account of Genesis in 1876. The effect on Victorian religious debate was immediate and loud, and the argument was often conducted badly, as a straight contest over whether Genesis had been shown to be borrowed.
The scholarly position is more interesting and more restrained. Enuma Elish and Genesis 1 share a cultural environment and some vocabulary of imagery, a watery formless beginning, the division of waters above and below, creation ordered into stages, and the Hebrew word for the deep, tehom, is cognate with the name Tiamat rather than derived from it. But Genesis 1 has no combat, no defeated deity and no divine corpse, and its God creates by speaking rather than by conquering, which reads in places as a deliberate refusal of the Babylonian pattern rather than a copy of it. Direct literary dependence is not demonstrable; shared inheritance and pointed contrast are.