Here, the greatest sin of Judah is not idolatry, but an unfaithful way of life. The people are mistreating each other -- instead of living together in harmony, there is selfishness and greed. Evidently, people were willing to do bad things to their neighbors (and maybe even family members) in order to "get ahead." Even so, this long warning of destruction and punishment is followed by a hope for reunification of God's people from the two kingdoms into one peaceful kingdom.
[links to Bible Gateway open in a new window]Reading the Bible in Its Entirety
If you are planning to read the Bible in its entirety, you should read Micah 1-2 today.