An elderly church deacon driving to Sunday Mass with a plaque on her windshield that says, “God is my co-pilot,” fatally struck a homeless man in Brooklyn, witnesses and officials said.

Eighty-year-old Lillian McTodd, dressed head to toe in white, struck the man as he pushed a shopping cart containing bottles on Gates Avenue in Bedford-Stuyvesant at around 10:30 a.m., witnesses said.

He was in the crosswalk, and McTodd had a green light as she made a left turn in her gold Chrysler 300C from Bedford Avenue onto Gates, police said.

“I didn’t know him, never saw him before,’’ the stunned woman told The Post after the accident, with the man’s body lying in the street about 15 feet away.

The unidentified victim had just turned in part of his massive haul of bottles and collected $6.35 in cash from a local beer distributor when McTodd’s car hit him.

“I heard the boom first. I looked up, and she was trying to stop,” said a witness, who asked not to be identified.

“She said she didn’t see him at all. She ran over him, and then the tire started screeching.”

McTodd, who is also a missionary, was just a block away from the Evening Star Baptist Church, where she was to attend an 11 a.m. Mass.

In addition to the plaque, she also had an open Bible on her dashboard.

First responders found the victim lying in the street and pronounced him dead on the spot, officials and witnesses said.

Police said McTodd will likely not be charged with a crime.