Byron and Amanda Neuhoff.

Byron and Amanda Neuhoff.

Photo: Missy Sprouse

Amanda Neuhoff of Dallas was a close friend of my wife, Devin, as they grew up together in Knoxville, Tenn., and so she became dear to me. She was 51 and the mother of four children when she died of brain cancer in June.

Mandy, as childhood friends called her, was always the life of the party. She lived by her own code of attitudinal upgrade: Hard times were good, good times were great, and great times were, in her words—adjectives no longer being sufficient—“awesomeness.” She was full of love.

Over the years I grew close to her husband, Byron. He had a quiet reserve about him. He cherished his wife and basked in her high-wattage glow, but dutifulness was his defining trait.

I thought they were opposites. But her suffering and death, and his reaction to them, taught me that while I wasn’t wrong about my friends the Neuhoffs, I wasn’t completely right.

When the cancer diagnosis first confronted her last August, Amanda colorfully described it to friends as a “throat punch.” Every day she fought for her life, but she never clung to it. Borrowing from 38 Special, a mainstay on her music play lists, she held on loosely, but didn’t let go until she was ready.

Through the suffering, Amanda expressed a preternatural sense of peace. All who sat with her saw it. At her funeral, many testified to it. This, I believe, was the calm that came from knowing her journey, while turbulent, would end in heaven. Inspired by this confidence, when cancer became Amanda’s cross, she bore it dutifully.

Byron never left his wife’s bedside, not for the long months at home, and not in hospice at the end. When his friends tried time and again to offer him the respite of a ball game or bike ride, Byron simply said: “I’m right where I want to be.”

Duty brings a good man to such a vigil, but it doesn’t keep him there so ceaselessly and tirelessly. Only true love does that.

Amanda, so full of love, dutifully drew closer to God through her suffering. Byron drew closer to Amanda and also to God, driven not by his mind’s call of duty but his heart’s call to love.

That’s what Amanda’s suffering and Byron’s care made me realize about my two dear friends. Amanda was loving, but more dutiful than I ever imagined. And Byron is dutiful, but also a husband who loved beyond measure.

When there’s no daylight between what you should do and what you want to do, duty is love and love is duty. Amanda died this way, and Byron lives this way. They weren’t that different after all.

Mr. Kerrigan is an attorney in Charlotte, N.C.