Weber County sheriff's Lt. Mark Lowther said congregation members at the Meadows Ward of The Church of Jesus Christ of Latter-day Saints in Plain City called deputies to the facility around 10:30 a.m. Sunday, The Salt Lake Tribune reported Wednesday.
Lowther said the Sunday service featured a baby blessing and a missionary "farewell" service.
"There was a pretty big congregation there that day and apparently a family member of someone being blessed felt he had reserved three rows of seats," Lowther said.
Lowther said another worshipper, a 51-year-old regular at the church, sat down at his usual spot, which was in the area the first man considered to be reserved.
The men argued, but the situation seemed to calm itself, witnesses told deputies.
"After the sacrament meeting, more words were exchanged, and there was a confrontation between the individuals out in the parking lot and the 51-year-old man ended up punching the victim," Lowther said.
He said the alleged attacker is also accused of attempting to hit the victim with his car, but the man jumped onto the hood of the vehicle to escape serious injury.
The 51-year-old suspect, whose name was not released, was restrained by congregants until deputies arrived. He was taken to the Weber County Jail on suspicion of aggravated assault and disorderly conduct.