The idea that Scripture has both “outer” and “inner” realities forms the basis for the apostle John’s thinking and writing. As St. Augustine put it, the New Covenant is hidden in the Old, and the Old Testament is unveiled in the New. It’s impossible for readers to fully understand the Gospel of John if they aren’t familiar with key Old Testament events. John begins by peppering his prologue with allusions to creation as recorded in Genesis. At the same time, it’s difficult to fully comprehend creation