Firefighters say people were inside the Lord House -which is part of the complex- having an all night prayer vigil when they heard a big boom.
"We heard this loud explosion," church elder Madge Joyner said. "At first we didn't pay any attention to it, and we continued on with our service."
But they all got out and noticed fire coming out of the neighboring Eagle Water Systems office.
Eagle Water Systems owner Cliff Whicker told Eyewitness News he never dreamed he'd spend his birthday in the charred ruins of his family business.
"I made a 20 minute trip in about 10 minutes," Whicker said. "My whole world fell apart. I can't tell you how devastating this is, it has been."
The complex is also home to Davenport Customs. Before the fire, they installed car stereos and alarms.
"The back part in the bay, where we do most of our work, just gone," Customer Service Manager Brandon Moore said. "Some of the inventory was in a separate office."
The businesses next to the church took most of the damage, while the church has just a hole in the ceiling, where firefighters checked for hotspots.
Church members are calling it a miracle that nobody was hurt.
"I keep telling people, I just can't believe how I saw the flames," Joyner said. "It was like two spirals, just protecting us. As you can see, we don't have anything burned."
They say their faith is stronger than before the blaze.
"It's been humbling," Whicker said."God's been with us. He's always going to be with us. I know where my faith's at. He's going to see us through this whole thing."
All the businesses say they will reopen, despite the damage.
Investigators are still trying to determine what exactly started the fire.