Several messages seem to run like a thread throughout the prophets -- even as they spoke to different audiences about differing issues. One theme is this: God desires mercy -- not sacrifice. Our obsession with what we do for one or two hours a week "in church" flies in the face of God's priority -- which is how do you treat people?
Another theme is justice. This is similar to the idea of mercy. God wants us thinking communally. What is best for the whole -- not just what is best for me and mine. That's something to consider at election time.
Another theme is that God wants humble people. As James wrote: "God opposes the proud, but gives grace to the humble." This was played out in God's dealing with nations in the days of the prophets.
Maybe it boils down to this: God wants people who reflect His heart. He wants us to love people the way He loves people. So there it is. Summed up by Micah (6:8): "He has shown you, O man, what is good. And what does the Lord require of you? To act justly and to love mercy and to walk humbly with your God."