"Football is not a matter of life and death, it is more important than that."
Faithfulness
You people in Judah and Jerusalem have been unfaithful to the LORD. You have disgraced the temple that he loves, and you have committed the disgusting sin of worshiping other gods. And why isn't God pleased? It's because he knows that each of you men has been unfaithful to the wife you married when you were young. You promised that she would be your partner, but now you have broken that promise. Malachi 2:11, 12, 14
God hates divorce because it is an example of broken faith. Moreover it looks as if the Israelite men were not just trading their wives in for a newer model but were replacing them with foreign wives. The implication is also that when marrying foreign wives, they were buying into the foreign religion as well.
God expects consistency of life from his worshippers. Life cannot be compartmentalized. As we offer - or lead - worship on Sunday morning God is concerned that we are faithful in marriage and consistent in our lives the rest of the work too. Rick Warren helpfully points out that the Christian church has reduced worship to an hour on Sunday morning or even the music within the service. In reality worship is a 24/7 lifestyle activity of living our lives to please God.
The real point of this passage is the unfaithfulness of the people, of which marriage is a prime example. We are called to work in the world of sport; faithfulness will make us stand out!