Of all the Old Testament books, Joel is one of the shortest containing approximately 2,230 words. In fact, it can be read in less than 20 minutes by the average reader. But don’t let this bite-sized book fool you because it is packed full of interesting imagery, prophecy, eschatology, theology, astronomy, and mystery that scholars have been chewing on for centuries. Even today there are some unknowns when it comes to Joel’s book.

1. Time Period Unknown
One mystery is that unlike most of the other prophetic books, Joel gives no chronological markers to indicate when his prophecies were given. So scholars are forced to rely on clues from within the text itself. But there is not much to go on, and so various dates have been proposed ranging all the way from the ninth to the second centuries BC. Even though there is no consensus on when it was written, the good news as John Calvin pointed out, is that

“the theological message of Joel is unaffected by the issue of the date….”

2. Real or metaphorical locusts?
Another unanswered question is regarding the identity and nature of the army invading the land of Judah in Joel chapters 1-2. They are referred to as locusts which has caused an interpretive challenge. Is Joel using imagery or is he being literal? Some scholars understand this invasion as a real plague of locusts. But others see it merely as a metaphor for a human army (perhaps the Assyrians or Babylonians). So which interpretation is correct? Fairly good cases can be made for both views but there is a third way to interpret Joel 1-2 which would seem solve this dilemma. As some scholars have pointed out, chapters 1 and 2 appear to be describing not a single event but two: Chapter 1 a literal locust invasion and chapter 2 a human invasion. Evidence that these are indeed two separate events is found in the timing of them. Notice that Joel seems to be describing the locust plague in chapter 1 as a past event. But in chapter 2 the invasion Joel was warning the people about hadn’t happened yet.