Amos was a shepherd from Tekoa in Judah — a layman, not a member of any prophetic school: 'I am not a prophet, nor am I the son of a prophet: but I am a herdsman.' The Lord called him and sent him north to prophesy against the Northern Kingdom of Israel during the prosperous reign of Jeroboam II.
His message struck at the social and economic injustice of his time: those who 'trample upon the needy,' who 'buy the poor for silver and the needy for a pair of shoes' (Amos 8:4–6). He pronounced the famous indictment: 'But let judgment roll down as waters, and justice as a mighty stream' (Amos 5:24).
He was expelled from the royal sanctuary of Bethel by the priest Amaziah; tradition holds he was eventually killed.