A contemporary of Hosea and Jonah, Amos prophesied primarily to the NOrthern Kingdom, Israel, but also makes reference to the Southern Kingdom, Judah and Jerusalem. He prophesied during a time of great prosperity. This was the problem. The kingdom’s relative prosperity made them assume God approved of all they were doing. But their prosperity brought significant religious and moral corruption.
The key verse is 5:24 which says that true piety (true religious character) is expressed as social justice. God hates injustice and oppression.
Chapter one and two bring indictments against surrounding nations and Israel and Judah. God is full of wrath and judgment because of their treatment of people. In 1:6 slavery is described–the capture and sale of whole communities. 2:7 says they trample on the poor and deny them justice. The end of chapter 3 describes great idolatry as the nation turns to all sorts of other altars and idols.
Amos expresses the judgment and righteousness of God. They thought that as long as they did all the ritual, they could do whatever else they wanted. Not so diffrerent than many Christians today. We often mistake religious activity for faith. Taking up a space in worship or saying prayers and singing songs is not what God requires. He requires a heart that belongs to him and that means that MOnday through Saturday our lives are directed by what God has revealed in scripture and by what the HOly Spirit reveals to us through that word.
How many prophets spoke this message? Every one did in one form or another. Israel (as a whole) did not listen. 1 Corinthians 10 says that all this was written for our example so that we will not make the same mistake. Will we?