You have just gone through a national trauma that should never be visited upon any nation, but especially not a free and tolerant nation such as you have. It is going to take some time for you to heal, but you will.
The thing to remember is that these acts of terror, although perpetrated by one of your own, do not reflect badly upon your country or your way of life. They reflect only on the delusional and twisted mind of the one responsible.
As everyone knows, on September 11, 2001, the U.S. suffered its worst terrorist attack in its history. It resulted in two wars that have lasted now for ten years. But this won’t be your fate because you were not attacked from the outside based on ideological differences between your national policy and the radicals in another country. All you will need to do at this point is decide whether your terrorist was really a lone wolf or if he had collaborators. Chances are, he’s a lone wolf. And he’s been caught. Your courts will deal with him.
Although you will never forget this tragedy, it is best not to dwell on it or its cause too much after your original period of mourning. It does not in any way change who you are as a people. You are a free, happy, tolerant, and progressive society. You use the term undertrykkelse (oppression) to describe situations in other countries. It does not apply to you. Your problem is not systemic within your political system. Rather, it is systemic within factions of the various religious regimes that exist in every country in the world. As such, the same thing can happen in any country that is tolerant of those who do not ascribe to fundamentalist religious sects.
In this case, the terrorist was a fundamentalist Christian. How do I know he was a fundamentalist? It is because only fundamentalists are deluded enough to do anything in support of their dogma. Fundamentalists of any religion cannot tolerate openness or diverse opinions.
The only cure for this kind of terrorism is to wipe out religious fundamentalism. That cannot be done through legislation or oppression, because that would, by definition, mean that your society has become less tolerant of diverse opinions. Even most fundamentalists would not stoop to terrorism, so they should be free to believe what they want. But it is the fundamentalist mantra that leads those who subscribe to the faith to act in an irrational and radical fashion. Fundamentalism provides the delusion that leads some people to do crazy things. Some people just behave crazier than others.
In the U.S. for example, some Christian fundamentalists murder abortion doctors. These murderers carry their religious beliefs to an extreme end, but had fundamentalism not deluded them to begin with, there would have been no reason to carry out their violent acts. Other fundamentalists in American are not violent, but they seek to overthrow the current form of government through legal means, such as infiltrating Congress, state legislatures, and school boards. Their common goal is to turn America into a Christian theocracy. Your terrorist also had the goal of overcoming your government and way of life and thus promote a more fundamentalist, reactionary form of government more in line with his delusions.
Most Christians will denounce him as a bad apple that is not a “true” Christian. But to fundamentalists, nobody is a true Christian unless they are also fundamentalists of the same stripe, unless they harbor the same delusions. To Pentacostals, Catholics are not true Christians. To the members of the Westboro Baptist Church, Presbyterians, Methodists, even other Baptists are not true Christians. A “true” Christian is only a person who believes the same brand of Christianity as the one doing the judging.
Religion in general is a dangerous concept because it breeds fundamentalism. And fundamentalism feeds delusions which lead susceptible people to perform violent, antisocial acts. Fundamentalism of one kind or another is free to thrive in an open, tolerant society such as yours.
So don’t blame your way of life or form of government. It is a model for the world. But as with other nations who have free societies, there is a price. The price is that highly deluded lone wolves can thrive, unnoticed. The lesson is to increase your vigilance. But don’t become paranoid. This degree of terrorism has not happened to your nation in modern history. There is no reason to believe that this strike is part of a trend. It is most likely an isolated case that can be treated as such.
Your nation is now in deep mourning for those who were killed and for the survivors that were traumatized. That is a natural process that will run its course. Your nation does not have to make any drastic changes because of it. It is not the fault of your system, but the fault of fundamentalism in general, and the only way to combat fundamentalism is through education, and your educational system is among the best in the world. There is little more you can do but live life as you always have and hope that it never happens again.