Given that Augustine’s conversion implies a qualitative growth in his life, this paper aims to interpret the last three books (11-13) in his Confessions from an educational point of view. With this view, I argue, these books can be regarded as summaries of his educational theory as follows. After showing that his conversion results from an exploration of the inner self in book 10, Augustine suggests prayer as a significant way to higher understanding in book 11. To avoid this understanding only in a private sense, he insists that all knowledge we acquire should be rooted in universal truths in book 12. Despite those above, However, Augustine urges us to notice ourselves as limited beings in book 13. but he also emphasizes trinity in us as the potential to grow. This view allows us to consider the books 11-13 as a development history of inner growth.