The former SS guard being tried for accessory to murder has admitted that he helped Auschwitz function by sorting cash and valuables seized from Jews.
But Oskar Groening, known as the bookkeeper of Auschwitz, denied helping to facilitate the murders of 300,000 people at the death camp.
The court heard of his “indoctrinated obedience” which he said prevented him from “registering the atrocities”.
He faces up to 15 years in prison if convicted.
The charges against the former guard relate to a period between May and July 1944, during World War Two, when about 425,000 Jews from Hungary were taken to the Auschwitz-Birkenau complex in Poland.
Mr Groening acknowledged on Wednesday that by counting the money confiscated from prisoners he was an accomplice to the Holocaust.
But he insisted he was simply following orders.
“There was a self-denial in me that today I find impossible to explain,” Mr Groening said in a statement read by his lawyer.
“Perhaps it was also the convenience of obedience with which we were brought up, which allowed no contradiction.
“This indoctrinated obedience prevented registering the daily atrocities as such and rebelling against them.”
Pleas are not entered in the German system but in April the 94-year-old told Lueneburg state court he shared “morally in the guilt”.
After Mr Groening’s statement Auschwitz survivor Irene Weiss, 84, said she could never forgive him.
Ms Weiss said the guards who stripped prisoners of their valuables were in effect preparing them for the gas chamber.
She said she remembered arriving at Auschwitz as a 13-year-old and immediately being separated from her entire family except for her older sister.
She said she asked other prisoners when she would see them again.
“A woman pointed to a chimney and said: ‘Do you see the smoke? There is your family,”’ she said, according to a transcript of her statement from her lawyers.
She added: “If he were sitting here today wearing his SS uniform, I would tremble, and all the horror that I experienced as a 13-year old would return to me.
“To that 13-year-old, any person who wore that uniform in that place, represented terror and the depths to which humanity can sink, regardless of what function they performed.”
In his statement, Mr Groening said the personal stories of the co-plaintiffs during the trial had brought home the enormity of the atrocities.
He said: “I can only ask my God for forgiveness.”