Early Nov. 10, my phone rang with terrible news: My wife, Nancy, has a highly aggressive form of breast cancer.

Even as I type these words, I know there are countless readers who know the exact sensation. Either they’ve received a similar diagnosis or they love someone who has. And each of those readers knows the surreal feeling of having your life change instantly. Nancy and I lived in one reality before the phone call and another reality afterward.

It’s like the difference between peace and war. In peacetime, you can dream and plan. True joy may be elusive, but it seems like an attainable goal. In wartime, you dig deep. You fight. And the goal is not joy but survival itself. Peace has its many challenges, but war is emotionally shattering. The fight is so very hard and can feel unending.

Imagine how much harder that fight, any fight, would be if you fought it alone.

But ever since the deep darkness of that November phone call, Nancy and I have experienced countless bursts of light shining through, each one coming through the love and care from other people. My son immediately decided to give up his final quarter of in-person college and take his last classes online, so that he could move across the country back home to help his mom. Our church small group immediately started organizing meals. My friends from college raked our leaves so that I could sit with Nancy in chemotherapy. My fantasy baseball league collected funds for wigs.

And with each act of kindness and expression of concern — including from colleagues at The New York Times, who’ve demonstrated remarkable care and compassion — the darkness recedes further. Nothing is easy, and the fear is still real. But there is no comparison between the state of our hearts now and their state when we first received Nancy’s grim news.

The reason for our revival is rooted in a profound truth elegantly captured by an old Swedish proverb: “Shared joy is double joy. Shared sorrow is half sorrow.” I’ve heard that proverb many times. It was the refrain of a men’s prayer group that I belonged to for many years. But I had never felt its truth so powerfully until November, when our sorrow was so deep and the love of our friends so profound.

Last week, I watched my colleagues Adam Westbrook and Emily Holzknecht’s incredibly moving video essay, “The Life Span of Loneliness.” In it, person after person, generation after generation, describes the crushing burden of feeling utterly alone, sometimes even when they’re married or have good friends. A cancer survivor describes feeling abandoned. Middle-aged voices explain they don’t want to be a “burden” on others.

If you follow my writing, you know that I’m deeply concerned with the subject of friendship. As Surgeon General Vivek Murthy wrote in April, we are a “lonely nation.” Men and women have fewer friendships. An alarming percentage of Americans report having no close friends at all.

There is no national five-point plan for friendship. It’s not a problem susceptible to political or cultural fixes from the top down. Instead, it’s a problem that demands individual action motivated by individual conviction, perhaps led by the very people who know what it means to feel the double joy and half sorrow that sharing makes possible. Those of us who have been blessed in this way must bless others in return.

The key word in the Swedish proverb is “shared.” You don’t just tell me the reason for your sorrow or joy, and I don’t just listen. The word “shared” implies participation. When you share a meal, you are not merely one of two people eating. You are eating together. And so it should be with sorrow and joy. In the book of Romans, the Apostle Paul tells believers to “Rejoice with those who rejoice; weep with those who weep.”

At their heart, both the Swedish proverb and the verse from Romans are concretely describing what it means to be empathetic. As Brené Brown has memorably explained: “Empathy is a choice, and it’s a vulnerable choice. Because in order to connect with you, I have to connect with something in myself that knows that feeling.”

In other words, if you’re really sharing sorrow, you’re feeling it as well, and as you feel what your friend feels, you lighten your friend’s load. Brown continues: “If I share something with you that’s very difficult, I’d rather you say, ‘I don’t even know what to say right now. I’m just so glad you told me.’ Because the truth is, rarely can a response make something better. What makes something better is connection.”

Those of us who’ve experienced that connection and love should feel an urgent necessity to extend it to others. In our family, we have a rule: If we see someone alone and under duress, we try to help. No matter where we are. Nancy created this family rule, and no one in our family models it better than she does.

On a visit to the Vanderbilt oncology center just before Nancy’s second chemotherapy infusion, Nancy spied a woman at the check-in desk who had the same look of shock and fear that had covered her own face just three weeks before. So Nancy walked up and introduced herself. She asked the woman if she was OK, and the woman replied that she had just received her own diagnosis minutes before. She was all by herself. Most of her family was far away.

Nancy’s tears came almost instantly. She knew the shock of a cancer diagnosis. And at that moment, a connection was made. They shared each other’s sorrow. They’re hoping to share each other’s joy when they both beat this dreadful disease. But no matter what the future holds, they will not fight alone.

David French joined The New York Times as an Opinion columnist in January 2023. Before that, he was a senior editor at The Dispatch, which he helped start, and a contributing writer at The Atlantic. He spent most of his career as a practicing lawyer, working in commercial and constitutional litigation. In his late 30s, he joined the United States Army Reserve as a judge advocate general. David deployed to Iraq in 2007 and served in Diyala Province, where he was awarded a Bronze Star. He is a former president of the Foundation for Individual Rights and Expression. His most recent book is “Divided We Fall: America’s Secession Threat and How to Restore Our Nation.” He lives in Franklin, Tenn.