Kayla Mueller, the young human rights activist who was killed earlier this year while being held hostage by ISIS, was a woman of faith with a heart full of compassion toward those who suffered, her parents say. Now, they intend to carry on her legacy of service to others.

“Some people find God in Church, some people find God in nature, some people find God in love, I find God in suffering,” Kayla’s mother, Marsha Mueller told CNA April 18, reciting a phrase of her daughter.

“I’ve known for some time what my life's work is: using my hands as tools to relieve suffering.”

The Mueller’s shared their daughter’s story during an April 17-20 conference entitled “#We Are Nazarenes” in Madrid, Spain.

The title of the conference took it’s inspiration from the Arabic letter “nun,” which ISIS militants branded on the houses of Christians in Mosul, Iraq last summer to indicate which ones belonged to the “Nazarenes.”

The Islamic State – also known as ISIS – has taken over parts of Iraq and Syria in recent months. The militant terror group has established a caliphate and carried out mass persecutions of minority populations, primarily Christians and Yazidis.

Kayla Mueller, who came from Prescott, Ariz. and was 26 at the time of her death, was taken captive by ISIS militants in August 2013 while leaving a Doctors Without Borders hospital in Aleppo, Syria.

She had been working to help Syrian refugees along the Turkish border with international aid agency Support to Life, and had gone to the hospital to help for a day. Kayla and some of her colleagues were then abducted while being taken to a bus to return back to Turkey.

On Feb. 6, 2015, ISIS released a photo of a damaged building, naming Kayla and claiming that she had been killed in a Jordanian airstrike in Raqqa, Syria.

Her family confirmed her death Feb. 10, saying that ISIS had sent them proof in an email. The email held three photos of her body, bruised on the face and dressed in a black hijab – a veil that covers the head and chest.

Kayla’s parents, Carl and Marsha Mueller, recounted how their daughter had always been affected by the suffering of others, and that “her heart always broke when she saw suffering.”

From the time she was young Kayla had gotten involved with several volunteer organizations in her hometown, including youth camp.

She was good at speaking, so she got involved with different international groups, and had even been invited to go to Washington D.C. to meet with people as part of the leadership of the groups, Marsha recalled.

After starting her college career in environmental studies, Marsha explained that Kayla felt she wasn’t supposed to stay in school, but wanted to get her degree. She then changed her degree to political science with a minor in international relations and graduated in two and a half years.

Just two months after her graduation in Dec. 2009, Kayla traveled to India to work in an orphanage. When the weather got too hot, she went to the country’s northern border, where she worked with Tibetan refugees and taught them English.

She later went on to work in Israel, Palestine and France, where she studied for a year so she could learn French with the intention of doing mission work in Africa.

Carl Mueller, Kayla’s father, said that she truly shared in the suffering of those that she worked with. British philosopher and writer Bertrand Russell’s declaration that he had an “unbearable pity” for the suffering of mankind described how his daughter was.

That phrase, he said, “explains Kayla in as few words as you can possibly use. She truly suffered when she saw other people suffering and she had to help, she just had to help.”

In one letter Kayla wrote to her father while she was in India, she recounted how she had come home and was so angry about something that had happened that she was shaking.

What she managed to write down at the time was a shock even for herself when she read it later, Carl noted, recalling her words: “I find God in the suffering eyes reflected in mine. If this is how you are revealed to me this is how I will always seek you.”

Mr. Mueller said that after he received Kayla’s letter he wrote the phrase on a bookmark for her to carry with her in her travels, but she refused to take it. The bookmark now hangs on a wall in the Mueller home, alongside the various other gifts Kayla sent to her parents from abroad.

Kayla’s mother recalled how dedicated she was to alleviating and comforting the suffering of others, and said that her former declaration that “as long as I live I won’t let this suffering be normal,” is evidence of her determination.

“She looked at all people. Kayla was not narrow or selective. She had a real gift to learn from everyone, and she reached out to people that were different to learn from them,” Marsha said.

Despite how deeply she shared in others’ suffering, Kayla was always “fun-loving and joyful,” her mother explained, noting that she was always touched by how people with so little “still had so much.”

Kayla’s decision to travel to Syria rather than Africa, as she had originally planned, was the result of a chance encounter with a Syrian man while returning home from Palestine.

While on a layover in Egypt, Kayla met the man, who was not living in Syria but was visiting on holiday, and told him about the work she did.

Although he couldn’t understand why she would dedicate her life to others rather than looking out for herself, the man was touched by “Kayla’s love for people,” Marsha said.

The two of them kept in touch through skype and email, and once the Syrian crisis broke out the man went back to help his people because of Kayla’s influence, she recalled. He kept Kayla informed of the situation, and because of that she decided to travel to the Turkish border to work with Syrian refugees.

While on the border, Kayla worked with women whose husbands had either been killed, captured or were fighting with the Syrian Army.

Together with a few other colleagues Kayla helped to found an organization called “Dignity” in Arabic, where the women sold homemade baby clothes in order to raise money for their families.

Carl recalled how in one talk Kayla gave in their hometown, she explained that one of the women had asked her “Where is the world?”

“And Kayla, having no answer, said all she could do was sit and cry with them. That’s what she did, she comforted those people and she wanted to be where the suffering was the worst.”

Marsha said the last time they saw Kayla was at the end of May to the beginning of June, 2013 when she had come home for a 10 day visit, just two months before her abduction.

At the end of the visit, Marsha recalled how she sat on the couch with Kayla and held her hand, telling her “Kayla I just don’t want you to go this time, I want you to stay.”

Although the topic of conversation quickly changed, Marsha said that the next morning Kayla came out with a clay hand she had made and let dry in her room, saying “Mom, you’ll always have my hand.”

The expression became the inspiration and namesake for the Mueller’s nonprofit organization “Kayla’s hands,” which they founded after her death in order to honor her and continue her work in serving others.

After Kayla was abducted, her parents received ransom demands from ISIS, including requests for extremely large sums of money and the release or exchange of other prisoners.

The militants had even threatened them, saying Kayla would be killed if they spoke out, “so that’s why no one heard anything for 18 months,” Carl noted, and revealed that not even the rest of their family knew about the abduction for several months.

Marsha said that Kayla had always stayed in close contact with them through letters and skype, and that once they found out Kayla had been taken, she continued to write her daughter, and has 10 full notebooks of her correspondence detailing what was going on at home and “the miracles” they saw happening.

Faith has kept them going throughout the stress of the process, the Mueller’s said. "I don’t think we could have done it without faith.”

After the tension placed on them personally as well as their marriage in the face of making life or death decisions regarding their daughter, their relationship has been changed “forever,” Carl said, “but we have one thing, and that’s our faith. And it keeps bringing us back together and making us strong.”

Kayla’s message to the world, they explained, is that “one person can make a difference…one person with extraordinary faith, extraordinary compassion and extraordinary courage can make a difference, and Kayla has.”

They said that while they are just normal people, their daughter, whom they called “Special K” from the time she was little, was in fact the special one, and they want to continue her legacy.

The couple also made an appeal to the international community to make a greater effort in fighting against ISIS, saying that “If world had gotten together in 2013 when this group really formed, a lot of these kids would be alive, a lot of these families wouldn’t have their homes destroyed.”

“So there was a lot not done; people just kind of kept thinking it would go away,” Marsha said.

Her husband echoed her thoughts, saying that the world needs to band together and “bring this to a stop. It’s not the United States, we can’t police the world…it’s got to be all the countries and they’ve all got to do brave things.”