That is one of the major things about the Word of God that continues to completely blow all of my circuits. I do not ever get a full handle on a book, and 2 Peter is only 61 verses. Regardless of the amount of time you invest in digging through its text, you will never exhaust that mine. Further, a new believer who has never read the book will see something that you have never seen. That has happened to me more times than I can count.
About what other book can you say that? What other book continually challenges you not only in knowledge but in life?
I know of no other.