Before becoming a prophet, Amos was a sheep herder and a sycamore fig farmer. His prior professions and his claim "I am not a prophet nor a son of a prophet" (7:14) indicate that Amos was not from the school of prophets, which Amos claims makes him a true prophet. Amos' declaration marks a turning-point in the development of Old Testament prophecy. It is not mere chance that Hosea, Isaiah, Jeremiah, Ezekiel, and almost all of the prophets given significant coverage in the Hebrew Bible, give first of all the story of their special calling. All of them seek to protest against the suspicion that they are professional prophets, because the latter discredited themselves by flattering national vanities and ignoring the misdeeds of prominent men.
The Bible speaks of his ministry and prophecies concluding around 762, two years before the earthquake that is spoken of in Amos 1:1, "...two years before the earthquake." The prophet Zechariah was likely alluding to this same earthquake several centuries later: Zechariah 14:5, "And you shall flee as you fled from the earthquake in the days of Uzziah, King of Judah."
Though he came from the southern kingdom of Judah, Amos aimed his prophetic message at the northern kingdom of Israel, particularly the cities of Samaria and Bethel.
Jeroboam II (c. 781–741 BCE), ruler of the Northern kingdom, had rapidly conquered Syria, Moab, and Ammon, and thereby extended his dominions from the source of the Orontes on the north to the Dead Sea on the south. The whole northern empire had enjoyed a long period of peace and security marked by a revival of artistic and commercial development. Social corruption and the oppression of the poor and helpless were prevalent. Others, carried away by the free association with heathen peoples which resulted from conquest or commercial contact, went so far as to fuse with the Lord's worship that of pagan deities.
Amos is the first of the prophets to write down the messages he has received. He has always been admired for the purity of his language, his beauty of diction, and his poetic art. In all these respects he is Isaiah's spiritual progenitor. What we know of Amos derives solely from the book that he himself authored. This makes it hard to know who the historical Amos truly was.
Amos felt himself called to preach in Bethel, where there was a royal sanctuary (7:13), and there to announce the fall of the reigning dynasty and of the northern kingdom. But he is denounced by the head priest Amaziah to King Jeroboam II and is advised to leave the kingdom. There is no reason to doubt that he was actually forced to leave the northern kingdom and to return to his native country. Being thus prevented from bringing his message to an end, and from reaching the ear of those to whom he was sent, he wrote instead. If they could not hear his messages, they could read them, and if his contemporaries refused to do so, following generations might still profit by them. No earlier instance of a literary prophet is known; but the example he gave was followed by others in an almost unbroken succession. It can not be proved that Hosea knew the book of Amos, though there is no reason to doubt that he was acquainted with the latter's work and experiences. It is certain that Isaiah knew his book, for he follows and even imitates him in his early speeches (compare Amos, 5:21–24, 4:6ff, 5:18 with Isaiah 1:11–15; Amos, 4:7ff with Isa., etc., 9:7ff, 3:12). Cheyne concludes that Amos wrote the record of his prophetical work at Jerusalem, after his expulsion from the northern kingdom, and that he committed it to a circle of faithful followers residing there.
The apocryphal work The Lives of the Prophets records that Amos was killed by the son of Amaziah, priest of Bethel. It further states that before he died, Amos made his way back to his homeland and was buried there.