Micah was a prophet (holy man). The Book of Micah is in the Old Testament part of the Bible.
Micah warned the people in Israel and Judah (Micah 1). God would punish them for their evil deeds. The people had cruel schemes. They were thieves. And they listened to false prophets (false holy men) whose words were lies (Micah 2).
God did not want terrible things to happen. God wants to teach people. And he wants the nations to be at peace (chapter 4). God promised to send a leader for Israel. This leader would be from Bethlehem. We now know that this leader was Jesus (Micah 5:1-5).
So, God accused the people (Micah 6). God did not want their gifts (Micah 6:6). God wanted them to be humble and to do the right things (Micah 6:8). But they refused to obey God. They were proud, and they did many evil deeds. This is why God would punish them (Micah 6:9-16).
But afterwards, when the people served God, Israel would become a great nation again (Micah 7:7-20).