"Originally, in the time of the judges before the people of Israel had a king, each Israelite family had its own land in an agricultural society where wealth was decentralized. But during the period of the monarchy, a small group of powerful people around the kings use legal and illegal methods to seize the land of many people. Those who lose their land fall into poverty, and the powerful become very wealthy" (Sider and Davis, 1263).So, Amos--a shepherd turned prophet (i.e. a regular guy who smells like animal dung), is called by God to speak about Israel's future destruction due to the systems of injustice they created. Amos is speaking this message to the fat-cats in Israel who have gained their wealth by oppressing others (Amos 2: 6-8; Amos 5:10-13). Sider and Davis mention that Amos's message is particularly unpopular given that he is speaking about the future during a prosperous time for Israel. Nobody takes him seriously, and in the end, it costs Israel when they are defeated and taken over by the Assyrians in 722 B.C.
You see: God hates injustice and oppression. He doesn't take either lightly. In fact, Amos 4:12 is ominous and terrifying: "'Therefore this is what I will do to you, Israel, and because I will do this to you, Israel, prepare to meet your God." Isn't this chilling?! I mean, seriously.
What strikes me so much about Amos, though, comes later in chapter 5:21-6:7. In this section God calls out complacency, security, and status.