So here is a bit more of what he wrote in his manifesto on justifying terrorism in the name of his Christian beliefs.
Indulgences
An indulgence is the full or partial remission of temporal punishment due for sins which have already been forgiven. The indulgence is usually granted by the church after the sinner has confessed and received absolution. The exception is actions committed by those men and women who, by virtue of their suffering, assists in the intercession for all Christians (participates in Crusades, activities which involve protection of Christians, Christian interests or Christendom itself). Indulgences draw on the storehouse of merit acquired by Jesus' sacrifice and the virtues and penances of the saints and martyrs. They are granted for specific good works and prayers.
Indulgences replace the shortening of those penances that was allowed at the intercession of those imprisoned and those awaiting martyrdom for the faith.
Crusading is not just a right, but a duty according to Canon Law
Canon Law, the ecclesiastical law of the Catholic Church, is a fully developed legal system, with all the necessary elements: courts, lawyers, judges, a fully articulated legal code and principles of legal interpretation.
Can. 992 An indulgence is the remission before God of temporal punishment for sins whose guilt is already forgiven, which a properly disposed member of the Christian faithful gains under certain and defined conditions by the assistance of the Church which as minister of redemption dispenses and applies authoritatively the treasury of the satisfactions of Christ and the saints.
Can. 993 An indulgence is partial or plenary insofar as it partially or totally frees from the temporal punishment due to sins.
Can. 994 Any member of the faithful can gain partial or plenary indulgences for oneself or apply them to the dead by way of suffrage.
Can. 995 §1. In addition to the supreme authority of the Church, only those to whom this power is acknowledged in the law or granted by the Roman Pontiff can bestow indulgences.
...Pope Urban II and Pope Innocent III granted indulgence to all future Crusaders (martyrs of the Church)
In 1095 during the Council of Clermont, Pope Urban II declared that he remitted all penance incurred by anyone (crusaders) who participated in the first crusade.
The Pope dispenses indulgences from a reservoir of grace tied to martyrs of the church, those men and women who, by virtue of their suffering, assists in the intercession for all Christians. In the 12th Century, Pope Innocent III, expanded the Crusade indulgence to include anyone assisting with such endeavours.
When we, the cultural conservatives of Europe seize power in approximately 5-7 decades, we will take the necessary steps to eradicate the corruption which is continuing to plague the Church (both the Catholic and Protestant church). We must ensure that we have Christian leaders who believe in; self defence, protection of Eastern Christendom and the protection of Christians worldwide.
All in all, he takes up ten pages justifying violence according to his understanding of Christian theology, not only liberally quoting the Hebrew Bible but the New Testament as well.
If he didn't care about Christianity, he wouldn't have bothered writing so many pages of religious justifications for his actions.
His use of religion to justify violence is strikingly similar to that of his avowed enemies, Islamists. This does not by any means prove that Christianity or Christian institutions are at fault for his actions - and as far as I know there is no huge support structure of Christian schools, media and churches that can be drawn upon to strengthen his twisted beliefs. They seem to have come out of his own head. I don't know if he would have done the same thing if he had been an atheist, as defense of Christianity in Europe seems to be one of his main motivating factors, but his psychosis cannot be blamed solely on his religion either.
Yet even though religion is not necessarily to blame for what he did, but it is a factor that needs to be discussed openly, just as it should be when Muslims (or Jews or Hindus) use religion to justify terror. And at least some Christians need to recognize that this problem could emerge in their churches, just as leaders of other religions need to take some level of responsibility whenever terror is done in their name. Pushing it off by redefining the terrorist as not being a member of that religious group is not useful or helpful - there needs to be some level of self-analysis to see what could have been done to head something like this off before it turned so tragic.
Most analysts and commenters are now heavily trying to spin Breivik's actions in ways that benefit their own pre-existing agendas, and we are seeing a lot of nonsense being published in the guise of analysis. (Yes, he quoted some Zionists in his writings, this does not make him a Mossad agent!) This spinning of a sickening terror attack is a shame, and it reflects badly on many prominent people on the right and the left. This is in many ways a unique case; it trivializes the victims to facilely simplify the story just so pundits can feel better about themselves by placing the blame squarely on their enemies.