(CNN) — The nurse told us the doctor wanted to speak with us immediately.
The phone rang and my husband picked it up. I pressed my ear against the handle, trying to hear as Rob listened.
“… tumor … it’s bad … hard year ahead,” was all I could hear the doctor say.
It was enough to know life had changed forever.
Zach, my 14-year-old son watched intently from where he sat across the room; he knew something was up.
“What do I tell him?” I wondered as I walked to him, my legs going weak as my mind processed the news.
I wanted so badly to protect him, but I couldn’t protect him from his own body. He needed the truth.
I sat in the chair next to him and said, “You have a tumor.”
Zach held my gaze for a moment then turned his head and closed his eyes as he processed the news.
My heart was breaking. In that moment he looked so small and vulnerable — not like the tall, confident teenager who ran down a basketball court with ease, but like the little boy who once cried through stitches the doctor’s office.
That little boy had quieted his crying, pinched his eyes shut and turned away from me when he realized I couldn’t save him.
After I delivered his tumor diagnosis, Zach and I drove home in silence.
I put a pot of noodles on the stove while Grace, 10, worked on her math homework from the table.
Zach went to his guitar lesson and Rob and I stepped into the living room so he could tell me everything the doctor said: It was a tumor. We would need to do a biopsy, and it could be cancer.
I sank down into a chair.
All sorts of questions and thoughts frenetically fired off in my mind. How could this be? Where did it come from? Would Zach be able to play basketball? How much school would he miss?
Like a punch to the gut, it finally hit me: Zach could die.
My mind became still.
I had a very clear image of God’s face turned to me and I remember thinking: He sees us. He is watching.
And I remember knowing that God was patiently waiting for an answer to a question: Do you trust me?
Did I trust him with my son’s life? Did I trust that he would give Zach, me and our family the grace we would need to get through this? Did I trust the God who allowed cancer?
Then another very clear thought entered into my mind. I am so happy that I got to know Zach — that I got to be Zach’s mom.
My answer was simple: Yes.
Ten days later, in November 2009, Zach was diagnosed with osteosarcoma, a rare and deadly form of bone cancer that strikes mostly children and teenagers.
A few days after his first round of chemotherapy, Zach and I were sitting together on the couch in our living room.
“What do you think God has in mind with this whole crazy cancer thing?” I asked.
From the very beginning I knew this was more than just a physical battle, it was a spiritual one.
Zach thought for a moment then answered, “I don’t know, but I think it’s for something big.”
We plowed through the treatment, the surgeries, the therapy, the torture of cancer.
It was grueling, yet somehow comforting to know that we were fighting and there were still weapons in our back pocket.
Until one day they ran out. There weren’t any treatments left.
Once again it was me and God and that same question: Do you trust me?
I didn’t want Zach to suffer! I didn’t want him to die. I pleaded with God to show me what to do, how to pray.
As I wrestled with God, I realized that what I truly hoped for above all else was heaven, and if Zach was ready to enter in at the age of 17, then how blessed I would be as his mother to see him on his way.
I gave Zach over to God. But I asked for something in return.
“If you must take him, if Zach must die, please let it be for something big,” I prayed. “Just one soul changed forever.”
And then “Clouds” rolled into our lives and something big happened.
Soon after Zach was diagnosed with cancer, I asked him if he planned to leave anything behind for his family and friends, something to remember him by.
We talked about whether he wanted to write letters to each of his close friends and family members, but that was the extent of the thought we’d put into it.
A few weeks later, I was straightening up the family room where Zach spent a lot of his time, picking up trash and dishes, when I noticed a crumpled piece of paper with song lyrics.
It was Zach’s first draft of “Clouds.” I thought the song was beautiful and heartbreaking, yet joyful.
I asked him if the song had been put to music, and he let me listen to a recording he’d taped on his phone.
I fought tears as I listened to his soft voice articulate such a deep and painful thing in a way that somehow lifted my spirit.
He had gone from seeing beauty in the midst of suffering to creating it.
He had taken the cancer that threatened to suffocate him and stripped it down until all that was left was hope. He had taken his eyes off of death and lifted them to the heavens, to eternity, to the clouds.
Over the course of the next several weeks, Zach worked with his guitar teacher, who had the equipment, to get the song recorded. We sent it to family and friends who had shared in our struggle.
When our local radio station in Twin Cities, Minnesota, asked if Zach would play a song for the station’s annual fundraiser for the Children’s Cancer Research Fund, he jumped at the opportunity.
While Zach originally sang Jason Mraz’s “I’m Yours,” that day, the producers thought the song’s lyrics were a little too upbeat for the content of his interview.
They asked if Zach would be willing to sing and play a different song. I sent them the recording of “Clouds.” They loved it.
The next thing we knew, “Clouds” had been professionally recorded, with a videographer on hand to capture the session.
And then it was on the radio. The local media picked up on our story, running interviews with Zach and the video.
We began receiving media requests from all over the country. Other radio stations began to pick up “Clouds” and our family got a crash course in how to balance the outside attention with the reality of Zach’s short time left with us.
As word got out that Zach didn’t have much time, Soul Pancake, the company that produces the “My Last Days” documentaries, got in touch with me.
As a family, we recorded a 20-minute mini-documentary. It was agonizing, but in hindsight, we’re so glad we have that tape.
As the “Clouds” video went viral, and as the song was picked up on radio stations around the globe, the letters started pouring in.
A lot of it was fan mail that Zach got a big kick out of, but most of it was heartfelt notes from people Zach had inspired to live life … well, better.
Zach had taken charge of the end of his life to show people how to live, and his message was being heard loud and clear.
Last May, Zach died. But his impact — and his song — have lived on. A week after “Clouds” jumped to No. 1 on both the iTunes and Billboard lists. It has more than 10 million views on YouTube.
Last year, CNN named Zach one of the most extraordinary people of 2013.
And I’m more certain than ever that that one tiny prayer was all it took for God to use my son’s battle with cancer to touch the lives of millions of people.
Laura Sobiech is a wife, mother of four, and author of “Fly a Little Higher: How God Answered a Mom’s Small Prayer in a Big Way.” The views expressed in this column belong to Sobiech.