Ababab, all 39 books of the the Hebrew canon had significance for the Israelite nation at the time they were written.
Paul writing his letters during the "conclusion" of the Jewish system of things made clear that they also were important to his day. Because we are now living in the "conclusion" of the world wide system they are vital also to us today.
(1 Corinthians 10:11) Now these things happened to them as examples, and they were written for a warning to us upon whom the ends of the systems of things have come.
Jehovah God told ancient Israel of the curses that he would bring upon that nation if they did not keep his commandments. Among the curses was to be plagues of locust - Deut 28:38. Joel 2:25 is nominated as one such plague.
Joel found fulfillment also in the first century as testified to by Peter when he quoted Joel 2:28.
Locust plagues are also spoken of in the book of Revelation which is undergoing fulfillment in our day.
What we need to be careful of however is endeavouring to give each verse an application for our day if in fact the Scriptures do not. The overall message is one of hope for those obedient to God's Word.
(Romans 15:4) For all the things that were written beforehand were written for our instruction, so that through our endurance and through the comfort from the Scriptures we might have hope.
