With the 1964 discovery of cosmic microwave background radiation—predicted by Big Bang theorists in the 1940s—the Big Bang theory became the preeminent cosmological model. The question was no longer, did the universe have a beginning? The question became, how did it happen?
As more and more astrophysicists focused their attention on what happened in the first few moments, months and years of the universe, some Christians became upset that the new theoretical models didn't match up with their interpretation of Genesis ( the Jewish account of creation is similar). Just as many astrophysicists felt that the expanding universe theory was a ploy to inject religion into science, many Christians have come to feel that the Big Bang is an effort to undermine the biblical account of creation. Other Christians, however, feel that the Big Bang is indeed consistent with the Bible’s account and they welcome such compelling evidence for the creation of the universe.
The Big Bang wasn't a sudden explosion of energy in some empty part of space at some distant moment in time. According to the theory, all space, time and energy came into existence together in that "bang." Before the Big Bang, there was no time. There was no space. Then, suddenly, an exceedingly dense, incredibly hot, infinitesimal ball of something – everything – appeared somewhere, somehow for reasons unknown and began to expand rapidly with our whole world inside of it.
Einstein believed in God not for theological - but for scientific reasons. As one Christian theologian put it, "I am not necessarily opposed to the Big Bang theory. Rather, I know who banged it." Physics is constantly changing, and perhaps one day the Big Bang Theory will join the flat Earth and the geocentric universe in the dustbin of history. But until it does, belief in God should not be dismissed.