U.S. Hostage Kayla Mueller Killed by ISIS Drew Comfort from Strong Christian Faith, Dedicated Life to Helping Others

Feb 10, 2015 02:01 PM EST

The family of Kayla Mueller, the female humanitarian aid worker and devout Christian held captive by the Islamic State terror group, said Tuesday it has received confirmation that she is dead

"We are heartbroken to share that we've received confirmation that Kayla Jean Mueller, has lost her life," a statement from the family reads.

"Kayla was a compassionate and devoted humanitarian. She dedicated the whole of her young life to helping those in need of freedom, justice, and peace," the family said.

The 26 year old Arizona native, who is the fourth American killed while held captive by the militant group, had traveled to Syria to help children affected by the nation's bloody civil war. However, in August 2013, she was kidnapped by the Islamic State while working at a Doctors Without Borders hospital in Aleppo.

During her captivity, Mueller sent her family an emotional letter, which they received in the Spring of 2014. Instead of focusing on her captors or her bleak situation, Mueller shared with her family how her experience had strengthened her faith in God.

She wrote, "I remember mom always telling me that all in all in the end the only one you really have is God. I have come to a place in experience where, in every sense of the word, I have surrendered myself to our creator b/c literally there was no else....+ by God + by your prayers I have felt tenderly cradled in freefall."

She added, "I have been shown in darkness, light + have learned that even in prison, one can be free. I am grateful. I have come to see that there is good in every situation, sometimes we just have to look for it. I pray each each day that if nothing else, you have felt a certain closeness + surrender to God as well + have formed a bond of love + support amongst one another."

Mueller was extremely devoted to her work, her parents, Marsha and Carl Mueller, said in a statement Friday."The suffering of the Syrian refugees drew Kayla to the Turkish/Syrian border ... to assist families who had been forced to flee their homes," her parents said. "The common thread of Kayla's life has been her quiet leadership and strong desire to serve others."

According to BBC, Mueller participated in humanitarian endeavours for most of her life; by the time she was 19 years old, she had volunteered with the Save Darfur Coalition for three years, written letters to Congress, and organized silent local walks to raise awareness about the issue, according to the profile.

After graduating from college, she spent time in India teaching English to Tibetan refugee children in an orphanage, and later spent a year working at an HIV/AIDS clinic in Arizona, volunteering at a women's shelter at night, according to the Christian Science Monitor.

Mueller traveled to the Mideast in late 2012, where she spent time in Turkey helping refugee families fleeing violence in Syria with the Turkish humanitarian organization Support to Life.

"For as long as I live, I will not let this suffering be normal," Mueller said at the time. "[I will not let this be] something we just accept."

On Tuesday, U.S. President Obama released a statement insisting that no matter what it takes, the United States "will find and bring to justice the terrorists who are responsible for Kayla's captivity and death."

He added, "Kayla's compassion and dedication to assisting those in need shows us that even amongst unconscionable evil, the essential decency of humanity can live on."

Billy Graham Evangelical Association President and CEO Franklin Graham has encouraged Christians to pray for Mueller's family in the wake of her tragic death.

"Today the family of 26-year-old Kayla Meuller has been informed that their daughter is dead," Graham wrote on his Facebook page on Tuesday. " We need to pray for her parents, Carl and Marsha Mueller, and her brother. Kayla had dedicated much of her life to serving others and had been working in the Middle East caring for the suffering victims of the civil war in Syria. She was kidnapped by the Islamic terrorist organization ISIS and held for 18 months. I am sure she will be greatly missed by all those who love her and those she was helping."

Sen. Lindsey Graham, R-South Carolina, said Mueller should be remembered for her selfless work, not for how she died.

"Her family's got to be heartbroken, but my God, this is the best example, this young lady, of being an American, being a decent human being that one could imagine. I believe very strongly she is in God's hands," he said on CNN Tuesday.

"Those who captured her, and in my view, killed her -- I think God will judge them differently."