Amos pronounced the impending judgment of God against Israel and Judah for their sins and failure to heed the repeated warnings of God's prophets. Amos was probably the earliest of the minor prophets to minister, preaching in Israel sometime between 770 and 748. 

Chapters 1 and 2 consist of oracles against the nations, concluding with alarming pronouncements against Judah and Israel. Chapters 3 through 5:17 consists of messages—this word—against Israel, followed by two woes against them (5:18ff, 6:1ff). Amos then recounted visions of judgment against the nation (7:1-3; 7:4-6; 7:6-9; 8:1-3; 9:1-4). The book concludes with a message future hope for a remnant (9:11-15). 

While Joel emphasized the hopeful aspect of the coming Day of the Lord, Amos warned the nation that because of their sins, they should not expect salvation (5:18-20; also 3:14; 6:3; 8:3; 8:9, 13). Amos uniquely paid little attention to the nation's idolatry. He condemned altars in Bethel (3:14) and mentioned their images of a false god in 5:26. Amos also condemned their false worship several times (2:4; 4:4-5; 5:21-24). But he primarily focused on the pervasive disregard for the rights of the poor. Amos repeatedly called out Israel for their failure to act justly and care for the weak (2:6-8; 3:10; 4:1; 5:11-12, 15, 24; 6:1, 4-7, 12; 8:4-6). While the judgment in Amos seemed unavoidable (5:25-27), his message concluded with a message of redemption for the survivors of the exile (9:11-15). The passage assured the people that God's everlasting covenant with David had not been forgotten. 

The New Testament recognized that Amos 9:12 has been fulfilled by the inclusion of gentiles into God's Church (Acts 15:15-21). Amos' message clearly describes God's concern for the weak, His anger against those who abuse their power, and His ultimate salvation of those He has called.