Malachi was a prophet of God 400+ years
before Christ after Israel returned to their land from Babylonian captivity. Once they were out of immanent danger, they slowed their pursuit of God, and lulled into a mediocre commitment to God. They believed the lie often embraced today, “I’m okay spiritually.
I do not need to push the limits or go crazy with God.” Even the priests coasted spiritually and lowered the bar of what was acceptable in the people of God.