A 25-year-old who killed her great-grandmother and her former boyfriend was insane at the time of the deaths, the Old Bailey has heard.
Phiona Davis, of Green Lanes, Palmers Green, north London, was found not guilty of murder due to insanity.
The student had told doctors she thought Keith Fernandez was a robot and her great-grandmother Mary Skerrit was the devil, the jury heard.
Both were found with multiple stab wounds in October last year.
On Tuesday, the court heard that Miss Davis had said she had attacked them because she thought "judgment day" had arrived.
Miss Davis was also found not guilty of arson by reason of insanity. She had denied all of the charges.
She was given a hospital order under section 37 of the Mental Health Act with a section 41 restriction, meaning she can never be freed without permission from the Home Office.
The 25-year-old was returned to Broadmoor special hospital where she is being treated.
Judge Martin Stephens told her: "When you committed these appalling acts of violence, you were suffering from a severe schizophrenic illness."
He said forensic psychiatrist, Professor Nigel Eastman, had called her "one of the illest people he had met in over 20 years".
Mr Fernandez, 27, was found with 58 stab wounds and 81-year-old Mrs Skerrit was discovered with 130 stab wounds a day later, at her home in Stoke Newington, north London, after a number of fires had been started there.
David Evans QC, prosecuting, told the jury Miss Davis had stood outside Mrs Skerrit's flat holding her hands outstretched and said "I am the Messiah".
He said she had shown some manic behaviour in 2002 and expressed interest in the church, saying God was speaking to her.
She had become a regular worshipper at the Kabbalah Centre in early 2003.
"In April 2003, Miss Davis's general practitioner notes that Miss Davis had been involved in prayer at church, she reported feeling controlled by the church," Mr Evans said.
"She felt scared living alone, she was not eating or drinking properly.
"She reported feeling that people from the Kabbalah Centre were walking around her flat."
Miss Davis had been discharged from hospital twice after her psychotic symptoms disappeared following overnight stays.
The court was told she failed to keep follow-up appointments, but had since responded to medication and was now "extraordinarily distressed by what she has done".