He said he acted after church members voiced fears the Obama administration could tighten gun control laws.
When the service began, some 200 people were present, AP news agency said.
"We are wanting to send a message that there are legal, civil, intelligent and law-abiding citizens who also own guns," Mr Pagano told the congregation. "If it were not for a deep-seated belief in the right to bear arms, this country would not be here today," he said.
The pastor also held a handgun raffle, as well as providing information on gun safety. I wish more churches did this, I wish more people did this," the Louisville Courier-Journal quoted one attendee, Doreen Rogers, as saying. "For some reason, most people think that carrying guns is sinful. It's not. I think my life is worth protecting."
full story from the BBC