No shots were fired in the harrowing incident at Boiling Springs' Southside Freewill Baptist Church, the Spartanburg Herald Journal reported.
Police arrested Jesse Gates, 38, who also was carrying a hunting knife, and his sister, Angela Michelle Gates, 34, who drove him to the church, the newspaper said.
The Rev. Henry Guyton said Gates had shown up before the service acting "like he was having a heart attack" and asking that someone call a television station. Guyton said he called 911 instead. Deputies and emergency medical services staff checked out Gates and he left the church, only to return with a shotgun, the Herald Journal said.
Guyton's 26-year-old grandson Aaron was in a recreation building next door and saw Gates take the gun out of the trunk of a car.
"At that point, I knew I had to do something," the younger Guyton said. "I wanted to try to contain him outside."
Aaron Guyton went in the church and locked the doors, but Gates forced his way inside where the church members took action. Jesse Smith and Leland Powers held the gunman down while Aaron Guyton, who has a conceal-carry permit, held a gun on him until deputies arrived, the newspaper said.
"The gun was loaded," Henry Guyton said. "I said, 'Jesse, what did you do it for?' He said, 'They took my children and won't let me see them.'
"I'm glad the Lord took care of everything. The police did a good job too."
Gates was charged with second-degree violent burglary, disturbing a place of worship, kidnapping, and three counts of pointing and presenting a firearm.
Gates' sister was charged with accessory before the fact of a felony.
Spartanburg County Sheriff Chuck Wright commended Aaron Guyton for having a concealed weapons permit.
"We're very fortunate we didn't have gruesome scenes to work there," Wright said. "I like the fact that a concealed weapons permit holder was prepared to protect the worshipers."