What it implies is that the Big Bang and religion are not two opposing viewpoints. You can say 'maybe the priest wasn't religious anymore', but that is a minority assumption. If he is a priest, it is most likely that he was religious. That is the simplest view. And if he is, it shows that religion and science have not always been, nor needn't always be, opposed (in fact, that 'opposition' is just a construct of the last 100 years. After all, some of the deepest thinkers of history, say in ancient Greece, were deeply religious, even while they questioned religion itself.)
The reason I said that is because someone said, instead of believing in God, that they believe in the Big Bang. But that means nothing. I believe in God, but also in the Big Bang.