Amos 5:24 is one of 27 times that the Hebrew word that is rendered “justice” in our Bibles appears in the minor prophets (Hosea, Amos, Micah, Habakkuk, Zephaniah, Zechariah, Malachi).
How would you define “just”?
A quick look at the web suggests that the current understanding of the Word is similar to the definition of “fair”. Fair is a concept that is talked about in politics, social media, and a myriad of other venues.
However, God is never described as “fair.” That is not the force of the Hebrew word. A quick survey of all of the uses of מִשְׁפָּט (mispat) seem to suggest that the term means alignment with the law. It is not fair in the sense that it is normally used today. It means compliance to the law.
Since in the Bible God is the source of the Law, one could suggest that “just” is in alignment with His nature and character.
It is not a subjective concept. However, fair, seems to be. There is significant debate on what is fair. However, one is either in compliance with a law or one is not.
There seems to be a distinct difference. Which begs the question, “Why is justice, so central in these books?”