Amos is the book of the herdsman from Tekoa, a small town in Judah. He receives a direct call from God to prophesy against the unrighteousness of both Judah and Israel. Amos is the first prophet to proclaim that God is the ruler of the whole world.

Amos 5

5:15 Hate the evil, and love the good, and establish judgment in the gate: it may be that the LORD God of hosts will be gracious unto the remnant of Joseph.