Small in size, the saints' relics provide a precious spiritual connection for parishioners at Ste. Genevieve Catholic Church.
Still, the church's pastor and police in Ste. Genevieve, Missouri, a river town settled by French colonists in the mid-18th century, are mystified as to why someone would steal nine of them.
They hold little monetary value and would be difficult to sell without their paperwork.
"We are kind of at a loss," police Sgt. Steven Poole told CNN Saturday.
The theft occurred sometime between Christmas Eve and January 4, when the dollar-coin-sized containers holding the nine relics were found empty. Those containers are displayed in larger vessels, called reliquaries, that sit on two side altars.
For many worshipers, saints help them get closer to Jesus Christ, according to the Rev. Dennis Schmidt.
Schmidt said the thief or thieves may have thought the relics, along with any small amount of gold or other metal with them, might make the job worthwhile.
Schmidt said he doubts anyone took the items, which can include portions of a saint's body or pieces of garment, for religious reasons.
"If they had taken one ... I can see that, but to take nine of them, it doesn't seem practical," he said.
"This will probably be something that will turn up somewhere once they realize there's no real street value," Police Chief Eric Bennett told CNN St. Louis affiliate KSDK.
The church has about two dozen relics, one of which belonged to Ste. Genevieve and was placed around the neck of her statue inside the church, said Schmidt. The relic of the patron saint of Paris is now in a secure location.
The relics have been part of the Ste. Genevieve parish since the 1930s and 1940s, when the pastor at that time brought them back from several trips he made to Rome and elsewhere in Europe.
"Some people are really upset ... (asking) why somebody would do this," Schmidt said of the theft.
Searches of area pawnshops have yielded none of the relics, Poole said. "We are hoping we can get help from the community, by word of mouth or at the church or (someone who) saw something."
Because of its history and decor, the church is popular with tourists visiting the largely Catholic town, an hour south of St. Louis. The parish was founded by Jesuits who came from Quebec.
Community leaders tout Historic Ste. Genevieve's heritage, charm and historic homes, some of which were built with distinctive vertical log construction. German immigrants who followed the French founders built rock and brick homes popular with visitors.
The town of about 4,400 is on the west bank of the Mississippi River.
Schmidt said the church, which serves about 1,100 families, will build a database to get a better handle on records and paperwork surrounding the relics. Leaders also are considering ways to secure the relics by placing them under glass attached to walls.
For now, he and others are praying for the return of the historic and spiritual items.
While Ste. Genevieve Catholic Church has insurance, the theft of the relics is no ordinary matter.
"How do we put value on it?" Schmidt asked.