The Rev. Shirley Petty, a chaplain at Hartsfield-Jackson International Airport's interfaith chapel, had planned to preach out of the book of Isaiah on Sunday.
"God has sent me back to something else," she said hours after the worst mass shooting in U.S. history left at least 50 dead and more than 50 wounded . "I just go with the holy spirit."
"Trust in the Lord with all your heart; do not depend on your own understanding," she read from the book of Proverbs. MORE: Gunman may have had terror ties
Petty anointed first her own head with oil and then visitors' before offering her words of solace and comfort amid the tragedy in Orlando.
"In this life's journey we will go through ups and downs," she said. "All the trials we go through are storms. After every dark storm cloud, there is sunshine. We never walk through it alone."
Florida Gov. Rick Scott is calling the shooting at Pulse, an Orlando nightclub, "heart-wrenching" and says people who went into the building knowing there was an active shooter are heroic.
Scott urged people to donate blood. He says officials are doing everything they can. He says the massacre was "clearly an act of terror."
Officials have said they're investigating whether the incident was an act of terrorism.
At the airport, where the long security lines, X-ray machines and police dogs travelers have become accustomed to bear the lingering impact of the Sept. 11 terrorist attacks in New York, Rev. Petty takes seriously her calling to pray for those coming and going.
"The devil is busy," she said. "We have to stay strong. No matter how tough life may be, God is the rock."
The chapel is on the upper level of the airport atrium, next to the U.S.O. office, and Petty keeps a supply of prayer pendants in the shape of dog tags. They are imprinted with a verse from , Joshua: "I will be strong and courageous. I will not be terrified, or discouraged, for the Lord my God is with me wherever I go."
The chapel welcomes people of all faiths. A Menorah is placed above the desk where Petty works, and Bibles are on the bookshelves.
A person of the Muslim faith came into the chapel prior to the Sunday morning service, but offered to go elsewhere, concerned her prayers would interfere with the ones planned for the chapel. Petty urged the visitor to stay, or to come back later if she wished, saying, "I always want you to feel comfortable here."