In my astronomy class we will be discussing the origin of the universe soon; this of course includes discussion of the currently accepted theory of cosmological origins, the big bang theory. Just in mentioning some upcoming topics, I've already had one student (a Christian) raise her hand and protest. I cringe when this sort of thing happens, for two reasons. One, I don't believe Christians should be in the business of not allowing the current theories to be taught, and Two, Christians are often very misinformed about the big bang theory.
Christians often associate the big bang theory with an atheistic explanation of the universe (atheistic in the sense that the explanation does not require invoking a creator; the universe, in other words, has a naturalistic explanation). In fact, one of the big bang theory's original formulators and proponents was a Belgian priest by the name of George Lemaitre. While he based his theory on science, not his religious beliefs, there was a clear consistency between the traditional Christian view of the origin of the universe and the big bang theory. The establishment view of the time was a static, eternal universe; this preference can be traced back to the Greeks and was often considered the more appropriate, secular way of viewing the universe. Several decades after Lemaitre's initial proposal, some other astronomers had gathered some observational and mathematical support for the big bang theory. While the evidence was not conclusive, it certainly was worth paying attention to. However, this scientific work was largely ignored and ridiculed by the scientific establishment. Some scientists ridiculed the big bang as being a thinly disguised attempt to bring religion into the fold by characterizing God's initial creation event in scientific terms. The Pope also noticed the congruence between Christianity's creation event and the big bang, formally declaring that science had vindicated Christianity's long standing belief that the universe had a beginning. This of course further enraged the more zealous of the secular astronomers and probably further delayed acceptance of the theory.
So, in contrast to what people often seem to believe, the big bang theory actually can quite easily be seen to support (or at least be compatible with) the initial creation event of Christianity. In fact, there is more tension between an atheistic worldview and the big bang than there is between Christianity and the big bang (a side note: I do not consider it wise for Christianity to ally itself too closely with any specific theory). After all, an eternal universe does not require a starting point, and therefore, no creator. The big bang theory posits that the universe itself (including space, time, and all known laws of physics) originated during this singular event. The implication is that something outside of space, time, and the known laws of physics must be responsible for the initiation of this event. This has not gone unnoticed by secular astronomers, hence the efforts by scientists such as Stephen Hawking to escape the conclusions of their own work by mathematically wriggling their way out of a universe with a beginning (Hawking uses imaginary time to circumvent an actual beginning, preferring instead a self-contained universe with no possibility of a creator).
To sum up, Christians need not fear the big bang theory (or embrace it too closely). Rather, we can observe the shared characteristics that it has with Christian beliefs and watch where the science leads.