I say that the story is driven by religion because it all goes back to the Bible in one way or another. Yes, Augustine does go into Philosophy for years in his life, and also teaches it, but he also goes back to being a Christian when he is older. Why would he be asking God for forgiveness if he was a Philosopher? Philosophers have a way of thinking, and were known to be the wisest men. However, it is also a deadly sin to think and/or say that you are better than our Creator. For example, Lucifer was God’s favorite, he was the most beautiful angel. He also knows the Bible by heart, which is how he used it against God. The reason Lucifer fell was because he tried to overthrow God. He wanted to be God.
Considering the fact that the pear-theft story goes with the Ten Commandments, Adam and Eve, and the story of Lucifer, they are all part of the Christian religion, and the Bible. There are more things that you can connect to Christianity/religion than philosophy. Throughout book one and book two, Augustine mainly talks about God and how God is everywhere, but you cannot seem him. Which is why you have to have faith in him and he will be there for you if you believe and have faith in