Volunteering can bring its own rewards: the satisfaction of helping others; the knowledge you're making the world a better place; the smile on another person's face and their expressions of gratitude.

For some people, though, volunteering has brought unexpected returns, benefits they had never imagined when they started giving back.

As millions honor the legacy of Martin Luther King Jr. on Monday by volunteering or participating in Day of Service projects, here are a few stories of people who found new paths − and passions − by donating time, energy and love to their communities.

(Scroll down to see how you can volunteer.)

She lost her son to fentanyl, then gained a 'family'

Tonya Doucette's son battled addiction after being introduced to liquor and drugs by an adult family member as an adolescent. But after stints in rehab, he seemed well on the road to recovery with 15 months of sobriety under his belt.

Trey Comeaux had resisted triggers when he returned in late 2020 to Lake Charles, Louisiana, after an extended stay at a Texas rehabilitation center, telling old friends nicely but firmly that he was sober. Most respected his recovery, Doucette said, but one friend asked that he hold onto some pills for him. Trey agreed, and, struggling with sleeplessness (not uncommon for people in recovery, doctors say), he took one.

He didn't know it was fentanyl, and it killed him. He was 21.

Doucette was devastated. But she's turned her pain into purpose, and in the process she has also found herself among a loving, supportive and understanding community of activists.

A detective investigating her son's death noticed she knew a lot about addiction and shared her frustration that there were few resources in Louisiana, especially for teens like Trey. He suggested she start a nonprofit, and though Doucette initially resisted the idea, she said, "God landed in my heart and He got me to do it."

In September 2021, she launched Project Trey. The nonprofit offers training sessions to educate people on the disease of addiction, its impact on families and how to administer Narcan, the opioid overdose antidote.

Shortly after the new year began, Project Trey Recovery Cafe had its soft opening in Lake Charles. Doucette, a lifelong Louisianan and self-described "full Cajun," said there are few resources for people in recovery in the area. Addiction still carries a heavy stigma there, too, so the cafe is a safe place where people can enjoy what they might at any other venue: music, billiards, karaoke, friends − all in a setting that supports and encourages their sobriety.

Doucette has also joined hundreds of parents, siblings, grandparents and spouses who've lost loved ones to opioids in protesting and advocating for change in Washington, D.C., and throughout the country. She has treasured friends including Dan Schneider, a Louisiana pharmacist who was among the first people to recognize the opioid epidemic; and Ed Bisch, a New Jersey activist who has worked to hold pharmaceutical companies and their owners accountable for their role in the crisis.

"Every year, I get on a plane and go to Washington," Doucette said. "We all meet up, and we share ideas about what's working and what's not" and collaborate on ways to help people fighting addiction and their loved ones.

Like Doucette, Bisch and Schneider both lost their sons. She said they all belong to a group no one ever wants to join. But that is, in itself, a form of solace.

"This is the only comfort that is real," she said. "They're the only ones who really understand. ... You're never the same (after losing a child), but there is huge comfort in being around other families, other parents who understand how you feel.

"People ask, doesn't that make it worse? No. ... If I didn't have these people, I don't know where I'd be. You're missing a part of your heart, but this is what gets me out of bed. It's the way I find purpose in the pain."

A 'leap of faith' from the corporate to nonprofit world

Russ Snyder built a successful career over more than two decades, doing regulatory work in the energy sector. But he was also active in the United Methodist Church's volunteer ministries, traveling the world on mission trips to Russia and Honduras, working in Appalachia, participating in a prison ministry.

In 2008, he found himself wanting a change, craving a career that was more meaningful. He began applying for jobs in the nonprofit sector, though he had no prior experience in human services, and he did some firsthand research on Volunteers of America, one of the country's largest social service organization.

Volunteering at a food pantry/shelter in Arlington, Virginia, Snyder saw the on-the-ground impact VOA has on people struggling with poverty, addiction, homelessness and other challenges. He applied for a job with the organization, and by January 2009, he started.

Now the president and CEO of VOA Chesapeake and Carolinas, Snyder said he was fortunate to meet and work with mentors who helped his transition from the for-profit to the nonprofit sector.

"You're literally building a family through the organization," he said. "I've met so many great friends and colleagues. You don’t have that in the corporate world. Everyone is out for yourself, it's about making money."

He still works in the field from time to time and said the rewards come in the form of tearful thank-yous from veterans, letters from people in recovery, and the people who tell him how VOA has helped them rebuild their lives.

"It's not an easy job," he said. "But it also doesn't feel like work. I get up every morning energized to do good."

VOA employees and volunteers "are out there in the trenches every day making an impact," he said. "Ask anyone in (nonprofit work), and they're not here to make money. You're helping people. And once you start, you never look back."

A post-career purpose; a friendship forged in history

"I couldn't just stay home and raise babies," Jackie Casper Agostini said.

After earning a degree from what was then Glassboro State College (now Rowan University) and working as a teacher, Agostini married and started a family with her husband. But, "always goal-driven," she wanted to do more, so she began volunteering, working with children and teens and with her Catholic church's ministries.

As her children grew up, Agostini earned a doctorate in psychology from Temple University in Philadelphia and launched a private practice.

But the octogenarian said that, for many women of her generation and prior ones, education didn't necessarily evolve into a career. Instead, they would volunteer their time and expertise. Agostini began researching and teaching women's history on a volunteer basis at community colleges and a library near her South Jersey home.

She learned about Susan B. Anthony and Elizabeth Cady Stanton, women whose legacies were preserved largely because they were prolific writers. Women, she knew, do the bulk of society's unpaid and low-paid work, so she encouraged women she taught to write their own stories.

"I knew, though, that I couldn't just tell a white story," she said. "As a white woman living in a very white world, I knew I had to expand my thought process. There are Black women and Native American women who are part of the history here, too."

She met Louise Calloway, a retired educator and social worker who founded a museum dedicated to the Underground Railroad in Burlington County, New Jersey.

Their friendship would last for years. Agostini eventually became treasurer of the museum and remains on its board of trustees. Calloway died in February 2023, and Agostini still mourns the loss while working to preserve her friend's legacy.

"It's such a gift to encourage other people, and Louise and I encouraged each other," Agostini said. "It was wonderful to have her in my life, and I treasure that, and through her I got to know all these wonderful women over the years."

How you can volunteer, on MLK Day or anytime

There's no shortage of ways to give back, and there are international, national and local organizations that need help. Here are some organizations that rely on volunteers, as well as some resources to find volunteer options in your community.

• Volunteers of America offers services for people dealing with homelessness and substance use disorder; post-incarceration and reentry programs; workforce development; supportive housing; veterans' services and mental health support. www.voa.org/
• Catholic Charities' ministries are for people of all religions and denominations and include housing assistance; refugee and immigrant services; disaster relief; food assistance and more. www.catholiccharitiesusa.org/
• The American Red Cross offers disaster relief; blood donations/drives; training for first aid, babysitting, CPR, swimming and health care workers; and aid to military families. www.redcross.org/
• Habitat for Humanity builds homes for people and families in need. www.habitat.org/
• United Way works to improve education, economic mobility and health for people in the United States and 37 countries and territories worldwide. www.unitedway.org/
• The Salvation Army is a Christian organization that helps people of all faiths and orientations through a variety of programs, including homeless services; services for the aging; food pantries; recovery programs; summer camps; disaster relief; LGBTQ+ outreach; veterans' services and more. www.salvationarmyusa.org/usn/
• AmeriCorps is a federal program matches people with volunteer opportunities in disaster relief; economic services; environmental stewardship; education; food assistance; veterans' services and more. https://americorps.gov/
• VolunteerMatch.org helps people find volunteer opportunities with organizations in their local communities. www.volunteermatch.org/
• Volunteer.gov matches people with volunteer opportunities with federal agencies including the National Park Service; Bureau of Land Management; U.S. Army Corps of Engineers; U.S. Fish & Wildlife Services; U.S. Forest Service and the U.S. Geological Survey. www.volunteer.gov/s/