The prophet teach us alot about the nature and Attributes of God as well as about ourselves.
They teach us about the Sovereignty of God. He is Sovereign over the Nations. Nothing is more central to the thinking of these prophets than the fact that God is the sovereign Lord of history and that nothing happens, either to Israel or to the gentile Nations that is not the result of His direct determination. The locust plague of Joel was His doing. The destruction of Nineveh was from Him. He rules supreme in the kingdoms of men, setting up one nation and putting down another, exalting one man and humbling another to the dust. Through it all, He rules supreme and He is working out His sovereign purpose. God is the potter. The nations are but vessels in His hand to make and remake as He wills. `Behold, as clay is in the potters hand, so are ye in mine hand, O house of Israel. Jer. 18:6 He has absolute power to dispose of the nations as He will, though He leaves them room to repent. Each Prophet always presented the two ways. Serve God and you will live; Curse Me and you will dies. Repent and God will avert the evil; Reject me and I will cast you off. Jer. 7:1-15.
God is faithful in keeping his promises. God is fulfilling His promises all throughout the Old Testament. No amount of sin or rebellion on man's part can alter His plan. Now we are waiting for the final act of History, the last Judgment of which the prophets spoke so often, when Christ shall return victorious on the clouds of heaven to judge the living and the dead and to gather His Church from every kindred and tribe and nation. Rev. 7:9
It was the prophets awareness of the holiness of God which lead them to their passionate preaching about sin. Take for instance the trihagion of Isaiah. Holy, Holy, Holy. It was Isaiah's encounter with the thrice holy God which prepared him for ministry. Isaiah 6:1-8 It made no difference where the sin was found, whether in foreign lands (Edom-Obadiah, Assyria-Nahum) or among God's people. Nowhere in the Bible are there stiffer denunciations of sin and heartier calls for a deep and legitimate repentance than in the Prophets. Apart from repentance judgement falls.
God is not only sovereign, faithful and holy, but he is also gracious, slow to anger and plenteous in mercy. Love is not incompatible with justice. Each Prophet had a message of judgment as well as words of encouragement to repent which issued out of a loving heart for God's people. Who knows if he will return and repent, and leave a blessing behind him. Joel 2:14. It is because of his great love for His people and even for Nineveh that he sends prophets with the message of judgment and even sending the judgment itself. God knows that sin is an outrage against himself, and humanity. He knows that sin is destructive so he judges it. He judges it in his own people so that they will turn back from sin to himself.
So in the prophets as well as in the rest of the Bible we see all the attributes of God: His goodness as well as His severity, His sovereignty as well as His faithfulness to his word. We see the sovereignty of God's holiness as well as His glory, power, love, mercy and grace. May we see in the sin of Israel and Judah our sin. May we be as the prophets, full of zeal for the glory of God hating sin and loving mercy and justice.
The Prophets Themselves
We also learn about the Prophets. Though we may not possess their prophetic gift, yet we may certainly model their lives and imitate their characters. The pre-exilic prophets lived out their days in a world very similar to ours. Isaiah 1:2-16 Broken homes, corrupt children, murder and chaos the order of the day, the church a mere ritual and tradition and threat from a world power hanging over their heads. Habakkuk 1
What was their attitude in the face of this desperate situation? They submitted to God in an attitude of faith, they surrendered their lives in God's service, they trusted in God completely and implicitly. Their lives were examples of holiness. They had seen God in all His glory and thus they had a right view of man. These men hated sin. They were horrified at injustices. They abhorred the arrogance of man because only God should receive glory. They were breakers of images, challenging all religious traditions, and shams. They were authentic, their lives exemplified their message and because of this, they were lonely, suffering men.
If you read the Quran, Hadith and Sira (Biography) of Muhammad (PBUH) you find God is sovereign, faithful kept his promise to his prophet of spreading Islam, Muhammad was holy, he talked about God love/justice and Muhammad had all the characters the author describe for a prophet.