Latisha Lawson, 31, forced her two-year-old son Jezaih to drink a vile mixture of olive oil and vinegar as part of a ritual to drive the devil from his body.
As he choked on the liquid she held her hand over his mouth to stop him vomiting and crushed his neck.
Jurors heard Lawson had wanted to drive a demon named as “Marzon” from her son’s body.
She had become convinced that her son was possessed and blamed herself because she did not profess her love for God while she was pregnant.
Lawson and another woman, who also believed her children were possessed, fed the mixture to four children at their home in Fort Wayne, Indiana.
Three of the children immediately vomited up the mixture, but Lawson held her hand over her son’s mouth to keep the liquid down.
An autopsy ruled he had died from having his neck compressed.
Police said Lawson kept Jezaih’s body in a plastic sack for more than a year after his November 2009 death until she was arrested on December 21.
Lawson told jurors she was convinced her son was possessed by demons as his behaviour had changed.
“I knew and believe I was interacting with a demon at that time,” Lawson said.
She said she kept her son’s body as she was convinced her son would be resurrected after his death
“I went in and just asked God to bring him back,” she said.
“He did it in the Bible. He did it with Lazarus. He did it with a child in the Bible.”
Defence lawyers had argued that Lawson was delusional and incapable of understanding right from wrong.
But prosecutors said there was no evidence to suggest the mother of two didn’t understand how wrong her actions were.
“Jezaih was an unwanted kid,” said Allen County Deputy Prosecutor Thomas Chaille. “This is a simple child abuse case. She still thinks she did the right thing. Scary.”
Lawson was convicted of murder as well as charges of neglect and battery of her four year old daughter.
She faces at least 45 years in prison when she is sentenced next month.