Killing is evil.
All killing is evil. This truth is a central tenet of Christ-centred morality. Even the killing of another person that is for the "greater good," or is merciful, or is defensive is an evil act from a Christian point of view. If we as individuals or in community are attacked and we kill to protect ourselves and each other we still have, although arguably innocent, to accept that we are somehow part of of the pervading evil inherent in our temporal existence that gave rise to the attack against us in the first place. We rejoice if we are victorious in a defensive war but we also know that we have, in total contriteness, to ask our God to forgive us for the evil we committed in achieving such a victory.
The killing of animals, for whatever reason, is also evil. We know this to be true because no creature will kill another creature in the Kingdom of God that is to come and which is our primary hope as Christians. The Kingdom is the perfection of creation that God strives for. Therefore, anything now that is not the same as it will be in the Kingdom, is less than perfect. It is tainted by the evil which will not be present in the g(o)odly Kingdom of the perfect God.
An argument can be made (and often is) that all acts of evil are equivalent. There are definite, strong hints in the Gospels that Christ ascribed to this view. Certainly, if we view evil from the point of view of the consequence of an evil act this appears to be true for specific types of evil. For example a soldier killed in battle is still just as dead as an innocent bystander killed in the collateral damage inflicted by a battle. But the human mind cannot help but include the perceived intentions in, or the lack of care of, an aggressive act in its categorisation of evil. The killing of a psychopath to stop him killing a child, to us, does not appear as evil as the killing of a child by a psychopath.
This is why the killing of Nigerian Christians as they celebrated the most joyous day of their year in their places of worship and sanctuary by Nigerian, Islamic terrorists yesterday fills us with the most acute abhorrence possible. The cynicism, the lack of empathy, the cold-heartedness of the perpetrators of these acts of carnage, compels us to despair at what we humans are capable of.
Non-Muslims throughout the world (the religious and those without any religious conviction alike) have shouted out their condemnation of these acts of barbarity. I assume that a high proportion of individual Muslims throughout the world have also condemned the atrocities in their hearts and have felt shame that they were committed in the name of their god.
However, this is not enough. When Christian Serbs committed obscene acts of mass murder against the Muslims of Bosnia, the governments of predominantly Christian countries not only condemned the acts of their fellow Christians but they actively sought to stop them committing more genocidal crimes or profitting from the crimes they had already committed. At this present moment, the governments of those Christian countries are supporting the democracy seeking, Islamic citizens of Syria who are being murdered on the streets or tortured in hidden prison cells everyday on the orders of the cruel dictator of their country. These countries are doing so even though they know that a true democracy in Syria will, more than likely, result in less of a Christian influence in Syria than was previously allowed.
The governments of the Christian nations are not perfect in goodness and good intention. Far from it, they are mostly self-interested to the extreme. But most of them are prepared to condemn evil that is committed by those who claim Christian allegiance as quickly as they are prepared to condemn the evil committed by members of other religions (although a government condemning itself for acts of evil is an extremely rare occurrence, of course). If there is to be any lessening, let alone the complete ridding of, acts of terrorist violence in the world, such as yesterday's bombings in Nigeria, then it is the governments of Islamic nations and those in clerical authority within the Muslim faith, who need to, not only loudly condemn acts of evil committed in the name of Allah, but also constructively act to stop further incidents of such violence.