Obadiah is one of the "lesser prophets." The book of Obadiah is a single chapter with only 21 verses. But just because it's small, it isn't unimportant.
His name means "serving Yah." And his words carry a message from the Lord.
Verse 15 speaks directly to the Edomites, the sons of Esau. Esau was the twin of Jacob, later named Israel. There has been bad blood between the Israelites and the Edomites for generations, just as there was dissension between Jacob and Esau. Family feuds seem to be carried on and on and on.
But in this verse, God says "The day of the Lord is near for all nations. As you have done, it will be done to you; your deeds will return upon your own head."
Gee, that sounds a lot like "Do unto others as you would have others do unto you." Our God is consistent about our conduct and the consequences of our actions.
God is the same yesterday, today and forever. He does not change. His requirements do not change. Obedience brings favor. Disobedience brings rebuke. It's a simple choice.
Help us to remember who You are and what You require of Your children. Keep us faithful to Your words and Your precepts. May we be all You would have us to be.
In Jesus' most precious name.