Church officials have said the building will likely be demolished at some point.
It will be the first time the public is allowed back to the church itself, which is expected to be demolished so a new structure can be built. Pomeroy has said it would be too painful to continue using First Baptist Church as a place of worship.
The gunman, Devin Patrick Kelley, died of an apparent self-inflicted gunshot wound after he was shot and chased by two men who heard the gunfire at the church. Investigators have said the attack appeared to stem from a domestic dispute involving Kelley and his mother-in-law, who sometimes attended services at the church but wasn't there the day of the shooting.
Kelley had a history of domestic violence: He was given a bad conduct discharge from the Air Force after pleading guilty to assaulting his first wife and stepson.
For Sunday's service, people from other churches dropped off handmade prayer cloths and tiny wooden crosses, among other gifts. Mental health organizations provided tissues and brought therapy dogs to the service.
Republican Sen. John Cornyn spoke at the service, saying lives were stolen as darkness overtook one man's heart.
"The pain of losing 26 members is overwhelming," Cronyn said. "Many lives have been changed forever . ... I can't imagine what you've been grappling with ever since."
On Saturday, about 100 people gathered outside the community center to commemorate
Veterans Day and honor the shooting victims, nearly half of whom had Air Force ties.
"Maybe this will start the healing process that will get Sutherland Springs and Wilson County to put this horrific tragedy behind us and look to the future," county Judge Richard Jackson, his voice breaking, told the Saturday crowd, which included first responders and law enforcement officers.
Jackson, the county's top administrator, thanked the first responders and others who rushed to First Baptist Church in the aftermath of last Sunday's shooting, which also wounded about 20 people. What they saw there will affect them the rest of their lives, Jackson said.
Sutherland Springs is about 30 miles (48 kilometers) southeast of San Antonio and not far from several military posts, including Lackland Air Force Base. The Air Force's chief of staff, Gen. David Goldfein, said 12 of those killed were either members of the Air Force or had family ties to it.
On Saturday, two silver hearses carried the bodies of another couple, Therese and Richard Rodriguez, to a small cemetery on the edge of Sutherland Springs following a funeral.
A steady stream of people also visited a makeshift memorial of crosses adorned with flowers, photographs, red hearts and white, purple and pink balloons. Among them was Jackie Lee, who traveled from San Antonio with several friends.
"It was on my heart since it happened," she said. "I needed to come to show the community some support, to show these people some support."
Christina Osborn and her children Alexander Osborn and Bella Araiza visit a makeshift memorial for the victims of the shooting at Sutherland Springs Baptist Church, Sunday, Nov. 12, 2017, in Sutherland Springs, Texas. A man opened fire inside the church in the small South Texas community a week ago, killing more than two dozen.