American Keith Broomfield, who according to his mother recently turned his life over to God, died as a volunteer fighter against ISIS on June 3 in northern Syria.
Donna Broomfield told NBC News from her home in Westminster, Massachusetts, "I didn't want him to go but I didn't have a choice in the matter. He turned his life over to the Lord and he decided this was God's will and God wanted him to do it."
Broomfield's mother told NBC that what she's waiting for now is "for his body to come back."
The State Department confirmed that Broomfield, 36, was killed in Syria fighting alongside the Kurdish Protection Unit (YPG) battling ISIS. He is believed to be the first American who has died volunteering to fight against ISIS.
NBC News reported that a woman named Jennifer Broomfield, claiming to be Keith's sister, posted pictures of her last text messages with her brother on Facebook.
In the text message Broomfield told his sister: "Sometimes you got to be a man whether you want to or not. I don't expect anyone to understand but I don't need anyone to either. I appreciate your concern and take it as a kindness."
She, too, paid tribute to Broomfield, saying, "My brother died to defend my sisters who are being sold, enslaved, raped and murdered."
She further praised him by adding that he's defending "my brothers who are shot and beheaded and dumped into piles of trucks."
Her posts about Broomfield, public on Facebook, also included a posting of the 23 Psalm. "I didn't think I would lose him," she said.
Broomfield's mother explained that he left the U.S. four months ago. The Kurdish militia also paid tribute to him on their Facebook page, according to the Daily Mail.
"He was a warrior with the courage and the heart of a lion," Kurdish forces said. They thanked his mother for "raising such a wonderful son," while promising revenge for killing "one of our brothers." In the post, Kurdish forces promised to chase ISIS "from our land to the gates of hell," praising Broomfield as a "martyr."
The Daily Mail also reported that dozens of Westerners have joined the fight against ISIS and The Christian Post reported back in April that American men, mostly former soldiers and Marines, are independently volunteering their expertise to fight against the Islamic militants.
At least one Australian and a British volunteer have died volunteering in the fight against ISIS. The two Westerners joined forces with the Kurds, who have been the most successful against ISIS.
Broomfield's sister-in-law, Melissa Broomfield, added confirmation to his mother's words. "He said God told him he had to go and without a second thought, he went," she said.
Broomfield was a production manager for the family's manufacturing firm before volunteering and paying his own way to join forces with the Kurds.
More than 3,000 U.S. troops are now in Iraq and the White House announced Wednesday that they are sending 450 additional troops to assist the Iraqi government in its fight to combat ISIS.