Obadiah is a prophet to the nation of Edom. Edom and Israel are related. Abraham had two grandsons named Jacob and Esau. Jacob was the father of the Israelites and Esau was the father of the Edomites. They should have been cooperating, but instead, Edom seems to enjoy making things difficult for Israel and watching them fail. Obadiah’s message to Edom is that they should not gloat over the coming destruction of Israel because they will meet the same fate. The house of Jacob (Israel and Judah) will someday be restored, but Edom will not.
God has to punish Israel and Judah for their disobedience, but that was no reason for an even less righteous nation to gloat. Those who have a relationship with God can look forward to God setting everything right, but everyone else should dread it! Edom makes the fatal mistake of seeing God’s judgment on their neighbors but fails to recognize God will judge their sin as well.