A judge in the South Gauteng High Court in Johannesburg was stunned by the claims of a convicted murder that she was a Christian even though she had committed heinous crimes over several years."You both said you are Christians but, the Christianity I was raised in doesn't believe in killings and robbing of innocent people. What went wrong here?" Judge Jacob Francis asked on Friday.Marinda Steyn is a former school teacher who is serving 11 life terms and 115 years behind bars for a string of murders. Her son Le Roux Steyn turned State witness and is currently serving an effective 25 years. The two were separately sentenced in May. Another man, John Barnard, is serving 20 years after he was sentenced in 2016.They were part of the so-called Krugersdorp killers, known as Electus per Deus (Chosen by God), who committed 11 murders between 2012 and 2016.Marinda Steyn is testifying in support of her friend, Cecilia Steyn, one of the alleged killers, who is standing trial with Zak Valentine and Marinda's daughter, Marcel Steyn. She has been on the stand since Wednesday.In court on Friday, the witness said she felt that she had done the right thing by confessing and that she felt God had forgiven her."My children have turned the other way. Maybe I have spoilt Le Roux as a child. I have been covering for him for many years," she added.But Francis questioned her claim that she was a Christian.Somebody is lyingFrancis also said he didn't know who to believe."Between you, Le Roux, John, Cecilia and Valentine, somebody is lying. This court has heard different versions. You are aware that some of the things in your plea statement are not correct."At what stage should I accept that what you are telling the court is true? Who should I believe?” the judge asked.READ: Krugersdorp killings: Court hears that child-like voices emerged from 'possessed' accusedProsecutor advocate Gerrit Roberts, SC, also put it to Steyn that she was testifying on behalf of Cecilia to exonerate her from the charges she was facing."You are prepared to take the fall for Cecilia and Marcel. With Marcel, I can understand. She is your daughter. I don't understand why [with Cecilia]," Roberts said.But the witness claimed she received a verse from God that she must confess and that God will forgive her.READ: WATCH: 'Killings not linked to satanism' – convicted murderer in Krugersdorp case"God wanted me to start a new life," she said.Steyn later asked for forgiveness: "This is the first time I am asking for forgiveness. I face the anger from the families. I see horror from their faces. They're still in pain. I am sorry for the anger and anguish I caused. It was never my intention to harm so many people."She was excused as a witness and the trial was postponed to March 13, 2019.