If the student is actually interested (and not just challenging you to try to get the class off-track) then you could suggest that the Old Testament does trace the development of one culture’s civilization, from the Patriarchs to the Exodus, and then in considerable detail from the wandering tribe, through the conquests and the era of the judges, to the rise and fall of the monarchies, the exile and the restoration of the kingdom, and finally the subjugation/occupation by the Greeks, who were of course succeeded by the Romans who were in control at the time of Jesus.
On the other hand, is he really asking why the Bible isn’t a history book, or is he asking why it doesn’t acknowledge the “progress” human beings have made, instead focusing on our failings? In which case you can perhaps ask him to consider some of current news in the light of God’s expectations of His people, perhaps to write an account of something from the news or recent history as if it were being included in the Bible.
We acknowledge that the people of God have, by putting the Covenants into practice, improved the lot of humanity - overturning the practice of human sacrifice, for example. But there are clearly many ways in which the Church has not overcome the sinful world, and places where She has failed to live out Her calling. This is why there are penitential rites incorporated into every liturgy.
Middle school kids are generally just discovering the world beyond their own circle - the news, politics, history. It’s an exhilirating and intimidating expansion! A big part of what you’re doing as a catechist is helping those expanding minds to take the faith they were taught as children into a more mature relationship with God. May He bless you richly for your efforts!
