How do you know 奥古斯丁 is not 上帝自己亲自拣选的人? The truth is that there are so many books and many of them contradict to each other. In the end it's the Pope who decided the list of books to be included in the Bible, so it's also the Pope decided who is 上帝自己亲自拣选的人!
You are confusing everyone perhaps even including yourself. The question is do you accept or reject his idea that church is the spiritual city of God, what is your answer?