Since the emergence of the Big Bang theory as the dominant physical cosmological paradigm, there have been a variety of reactions by religious groups regarding its implications for religious cosmologies. Some accept the scientific evidence at face value, some seek to harmonize the Big Bang with their religious tenets, and some reject or ignore the evidence for the Big Bang theory.

The Big Bang itself is a scientific theory, and as such, stands or falls by its agreement with observations. However, as a theory which addresses the nature of the universe since its earliest discernible existence, the Big Bang carries possible theological implications regarding the concept of creation out of nothing. Many atheist philosophers have argued against the idea of the Universe having a beginning – the universe might simply have existed for all eternity, but with the emerging evidence of the Big Bang theory, both theists and physicists have viewed it as capable of being explained by theism; a popular philosophical argument for the existence of God known as the Kalam cosmological argument rests in the concepts of the Big Bang. In the 1920s and 1930s, almost every major cosmologist preferred an eternal steady state universe, and several complained that the beginning of time implied by the Big Bang imported religious concepts into physics; this objection was later repeated by supporters of the steady-state theory, who rejected the implication that the universe had a beginning.

The view from the Hindu Puranas is that of an eternal universe cosmology in which time has no absolute beginning, but rather is infinite and cyclic, as opposed to a universe which originated from a Big Bang. However, the Encyclopædia of Hinduism, referencing Katha Upanishad 2:20, states that the Big Bang theory reminds humanity that everything came from the Brahman which is "subtler than the atom, greater than the greatest." It consists of several "Big Bangs" and "Big Crunches" following each other in a cyclical manner.

The Nasadiya Sukta, the Hymn of Creation in the Rigveda (10:129), mentions the world beginning from nothing through the power of heat. This can be seen as corresponding to the Big Bang theory.

THEN was not non-existent nor existent: there was no realm of air, no sky beyond it. What covered in, and where? and what gave shelter? Was water there, unfathomed depth of water?

— Rig Veda X.129.1

Death was not then, nor was there aught immortal: no sign was there, the day's and night's divider. That One Thing, breathless, breathed by its own nature: apart from it was nothing whatsoever

— Rig Veda X.129.2