I'm doing some research and am trying to determine whether the creation story of Genesis, chapter 1 (7 days-let there be light) is consistent with the Big Bang Theory. I am finding sources that contradict one another. I'd like to know if the Genesis story of creation is consistent with the Big bang theory solely from a Catholic point of view.
The Catechism of the Catholic Church has
Thus it may be seen that Catholic teaching, expressed in the Catechism, does not depend on the literal truth (or not) of Genesis 1. Other than a few brief words of literary analysis, it expresses no opinion — although St Augustine of Hippo certainly did. What is important is that Genesis 1 testifies that God created all that exists, and did so from nothing.
Although God is continually revealing himself and his methods, scientists have not reached the origin of creation, either by observation of the deep universe or by theoretical calculation. Even if one posits that the Big Bang was the means by which creation was effected, it is thought that everything emanated from a singularity: a point of infinite density and zero size — nothing.
128: Gen 1.1
The 1909 Pontifical Biblical Commission said:
See this for more info. So for Catholics there is no inconsistency.
Pope Pius XII spoke of the compatibility of the Catholic faith and the Big Bang theory in his 22 November 1951 speech to the Pontifical Academy of Sciences. (Unfortunately, I don't know of an English translation of it, but this machine translation isn't too bad.)