The man who opened fire on a Texas church Sunday was an outspoken atheist who thought Christians were stupid, according to his former classmates.

Devin Patrick Kelley, 26, killed 26 people – including 8 members of a single family – at First Baptist Church of Sutherland Springs, about 30 miles east of San Antonio. Kelley, who was a father of at least one child, often posted anti-Christian content on Facebook that drove several of his friends to block him.

“He was always talking about how people who believe in God we’re [sic] stupid and trying to preach his atheism,” former New Braunfels High School classmate Nina Rose Nava posted on Facebook. “I legit just deleted him off my fb cause I couldn’t stand his post.”

Facebook user Christopher Leo Longoria replied to Nava, saying, “I removed him off FB for those same reasons! He was being super nagtive [sic] all the timd [sic].”

Another classmate, who wished to keep her identity private, told the Daily Mail that Kelley “was different in school and creeped me out but never would I have thought he would do such a horrific thing.”

Yet another classmate, Patrick Boyce, said Kelley “was the first atheist I met. He went Air Force after high school, got discharged but I don’t know why.” As reported by Fox News, Kelley received a “bad conduct” discharge from the Air Force after charges of assault against his wife and child led to him being court-martialed. He was stationed at Holloman Air Force Base in New Mexico from 2010 until his discharge in 2014.

As for why Kelley chose to attack Sutherland Springs, he reportedly had in-laws who attended the church. However, they were not present at the time of the massacre, which killed approximately half of the church’s members and 4% of the town. Kelley reportedly used a Ruger AR-556 rifle in the attack, which he purchased legally last year. He attempted to get a carry license in Texas, but the state denied him.

If there’s one good thing about this horrific story, it’s the man who attempted to stop Kelley. Johnny Langendorff heard the shooting and confronted Kelley outside the church before chasing him down in another neighbor’s truck. Police found Kelley dead from a gunshot wound about 8 miles from the church, but it’s unclear whether he killed himself or was shot by someone else.

Share this if you’re praying for the town of Sutherland Springs, Texas.