The problems are most obvious with the priests in the Temple. Evidently, they find their service a terrible burden, and they complain about it. Worse, they are failing to uphold standards for sacrifices, allowing all sorts of imperfect animals to be offered on God's altar. Instead of giving God the best gifts, they assume that God will be happy with anything. Malachi reports that God is not happy at all, and God even wishes that the halfway sacrifices in the Temple would be stopped entirely.
[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 Malachi 1 today.