Kevin, I know you're a believer. Yes, the Bible is full of examples of dramatic reversals (Manassah springs to mind, and obviously Saul of Tarsus, etc) ... but there's a lot of sad stories of people who didn't change one iota, too. Even if you grant that God does "change" some people and soften their hearts, he apparently doesn't do that in all cases, and here on earth we're not privy to all the whys and wherefores. Therefore, I don't understand your contention that it is somehow "worldly" to believe that your wife may choose to persist/be allowed to persist in her current choices.
Humility dictates that we don't try to do God's job for him. You should persist in whatever course seems morally correct to you. But by detaching to a healthy degree, getting on with your life (no, I don't mean dating, I mean living your gift of life to the full) and accepting ALL possible outcomes, you demonstrate that you are putting yourself fully into His hands.
"Show me a completely smooth operation and I'll show you someone who's covering mistakes. Real boats rock." -- Frank Herbert