Lysa TerKeurst recently had to reread her own book to stop herself from adding one more thing to her schedule. For years, the bestselling author, speaker, mother of five, and director of the women’s ministry Proverbs 31, has reaped impressive results from her overstuffed schedule. But, says TerKeurst, “I started to sense a direct connection between an overwhelmed schedule and an underwhelmed soul.”

“How I set my schedule determines how I run my life,” she adds, “and how I run my life is how I spend my soul. I kept getting the sinking sense that I wasn’t spending my soul well.” That tension inspired her new book, The Best Yes: Making Wise Decisions in the Midst of Endless Demands (HCCP/Nelson Books, Aug.).

TerKeurst is author of the New York Times bestsellers Made to Crave: Satisfying Your Deepest Desire with God, not Food (Zondervan, 2010) and Unglued: Making Wise Choices in the Midst of Raw Emotions (Zondervan, 2012). The two books spent 40 weeks combined on the Times list. Made to Crave and its ancillary products (devotional, participant guide, study guide, ministry kit, etc.) have sold more than 1,370,000 units; Unglued and its ancillary products have sold more than a million.

Also president of Proverbs 31 Ministries, which began in 1992, TerKeurst reaches hundreds of thousands of Christian women each year with devotionals, a daily radio program, speaking events, and online training materials. She has appeared on Oprah, Focus on the Family, and many other media venues. Christian women are her main audience, but she says all women face similar struggles with too much “yes” and too little “no.”

TerKeurst recalls saying yes when she should have said no when she volunteered to make all the brownies for her daughter’s school bake sale. Busy as always, she waited until the last minute to bake the brownies and wrap them. “Then my daughter tells me, ‘All those brownies have nuts in them and we’re a nut-free school.’ So no brownies for the bake sale.”

TerKeurst is direct with women about the importance of controlling of their schedules. That means chasing down decisions and facing the end results--how will a task or commitment affect them and their families? Many women are caught between “the command to love and the disease to please,” she says, and need to realize that “every assignment is not my assignment.” She urges women to learn to say “the small no.” And sometimes that no is The Best Yes.

The Best Yes even provides women with scripts to help them learn to say no. “When someone asks you to do something, and deep down you know the answer is no, a small no said immediately gives that person a small, immediate sting,” TerKeurst says. “But if you delay, the no becomes bigger and more painful.”

It’s a struggle TerKeurst continues to have with herself. Ministry opportunities that look wonderful can seem reasonable to squeeze into her schedule, she says. “But every time I violate that deep ‘no’ or sense that this one thing will put me in that overscheduled place, it becomes a problem.”