Robert Scott Marshall and his wife, Karen, were both killed in the shooting.
They were both 56 years old and had recently moved from Pennsylvania to Texas.
They were attending First Baptist Church in Sutherland Springs for the first time.
His sister Holly Hannum said he went by his middle name, Scott, and called him "a great guy."
"He would have given you the shirt off his back and would've helped you do anything," she told CNN affiliate WTAE.
Robert was a veteran and worked on engines, his father told CNN affiliate WPXI.