Our kids are still at home, but my wife and I are preparing for our empty nest now.

Our daughter is 20 years old and spreading her wings. We expect our 13-year-old son to be around for a few more years. But we’ve realized that if we don’t prepare now, once the nest is empty our marriage might be dead.

God intended for a husband and wife to grow closer together. As the Bible puts it, they should be joined together as one flesh (Genesis 2:24). For too many couples, that doesn’t happen. The responsibilities of work and raising children turn their attention away from each other. Unless they make an effort to regularly connect with each other, they drift in different directions.

A couple can live under the same roof for years and not notice they’ve drifted apart until it’s far too late.

Laura and Bob Smith (not their real names) of Vancouver, Washington, worked as nurses in the same hospital. In the beginning, they had a lot in common. They chose shifts that made it possible to spend most of their time off together. When their first child came along, they sacrificed time with each other to avoid sending baby Kayla to daycare — one worked while the other was home.

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But their time apart didn’t keep them from finding time to have their second child, Kyle, two years later. Laura cut back on work to be at home more, but she still worked part time, taking shifts when Bob would be home with the kids.

As the two children grew, after-school music lessons and sports for the kids took the parents in different directions on the evenings they were both home. Weekends could be just as busy with games, concerts, and recitals. When time allowed, Bob Smith would squeeze in time for a round of golf with the guys on the weekend. Laura Smith, meanwhile, would go shopping with her girlfriends. Their family seldom spent time together.

Daughter Kayla went away to college after high school. Two years later, son Kyle enlisted in the Army. The day after he left home for boot camp, Bob handed Laura divorce papers and announced he was moving out.

He’d met “someone else” — a nurse at the hospital where they worked. Laura didn’t know how to react. She thought she should feel sad, or angry. But she felt nothing. For 20 years, while living under the same roof and sharing the same bed, they’d neglected to cultivate their marriage. Their marriage died long before Bob Smith announced it was over.

My wife and I are celebrating 27 years of marriage this year. It’s not by chance we’re celebrating a thriving marriage. We both feel more connected and more in love with each other than ever before. We’ve had challenges threaten our marriage. We may have challenges in the future. But we’ve committed to giving all we have to make our marriage satisfying to both of us. That commitment includes preparing for an empty nest.

If you’re married with kids, consider using these three tips for keeping your marriage alive and thriving for years to come:

1.) Start planning for an empty nest today.
Husbands, don’t wait for your wives to take the initiative. It can start with you. When the kids are asleep, or when you’re out together without the kids, ask your wife, “What’s your dream for us after the kids move out?” She may not have a dream to share right away. The point is to start a conversation. The question will get you both thinking about life after the kids move out. Share ideas until you both come up with a vision that is exciting to each of you. My wife and I have been discussing this for years. We haven’t always been excited about each other’s vision. We haven’t settled on a plan. Someday we will. But today we have fun imagining what our future might be like.

2.) Plan time together.
If you expect time together to happen without a plan, it won't happen enough. To cultivate a thriving relationship with your wife, planning time to be alone with each other is necessary. My wife and I have a one-hour "date" most weeknights starting at 9 p.m. If your schedules don't allow for daily time together, make it happen weekly if you can. If that's not possible, plan at least an eight-hour day together once or twice a month. Anything less that that will strain most marriages beyond what they can bear. If at least one of you is in a job that takes you away for weeks or months at a time, such as the military, make time alone a priority on leaves and calls home.

3.) Invest in each other's happiness.
Discover the things you do that make your wife happy, and do them often. Gary Chapman's best-selling book, "The Five Love Languages: The Secret to Love that Lasts," is a useful tool to help each spouse identify and "speak" each other's love language. My wife's first love language is quality time. Mine is physical touch. Knowing this, I've learned that the more time I spend with her, giving my full attention to her interests, the happier she is in our marriage. When she makes a priority of touching my arm, or holds my hand each day, I'm happy.

Start putting your plan for an empty nest into action today.

Jon Beaty, a life coach and father of two, lives near Portland, Oregon. He's the author of the book "If You're Not Growing, You're Dying: 7 Habits for Thriving in Your Faith, Relationships and Work."