The Book of Obadiah may be small, but it packs a powerful punch against the arrogance of Edom and other ungodly nations. It applies to both our past and future.
The Edomites, who were descended from Jacob's brother Esau, still carried the grudge their founder had for Jacob's deception. Worse, Esau's nation hated Israel even more. They refused to help Israel in their need, sold them as slaves, and even abused them while they were exiled to Babylon.
Through Obadiah, God declares judgment over Edom and prophesies that they will be erased from history. Babylon overtook Edom 100 years later, never to recover again.