You befriend someone who's a little sly, but full of potential. He provided company in a difficult time, so you return the favor. You invite him into your house to stay with your family. One of the first things he does is offer to negotiate a contract to have a big, nice fence built around your house. Sounds good. Except he negotiated that ruining your house and giving away your daughter to the enemy would be the price. Some deal, eh? Then, behind your back, he delivers your most precious resources into your sworn enemy's hands, resources without which you will eventually dwindle and die, and only brings them back under threat of bodily harm. He turns two of your allies against each other, completely alienating them so they wish to deal neither with you nor each other anymore, and all the aid and support they were lending you dries up. He raises a ferocious son, a predator destined to kill you, raises another son who does nothing but spit venom, and engenders a daughter who seems to bring sickness wherever she goes. He leads one of your sons into an ambush, and brings about the death of another one of your sons.
Now let's say that your family is somewhat important. You're in charge of watching over the weal of a number of surrounding districts and counties, who are depending on you to keep things in order. Your guest, it turns out, has no problem making deals with your enemies whose activities directly negatively impact the economic productivity of all the people you're entrusted to protect.
Finally, when you are assembled in a truce-hall, under cease-fire conditions, he shows up, kills one of the servants of the resident ambassador (with whose people you are in an uneasy truce), endangering the position of everyone in the hall, and then slanders every member of your family publicly, in front of those with whom a shaky cease-fire have been negotiated, and confesses openly to the murder of your son.
Some questions :
Would you ever welcome this person back into your house again?
Would you feel justified in calling for this person's execution or permanent exile?
Would you ever want to have anything to do with anyone who knowingly associated with this person?
Would you ever want anyone you love or protect utilizing this person as some kind of example or model?
Would you ever buy any argument that suggested that overall this person's actions represented a net gain to you and your family?
Have any of your answers been motivated in any way by Christian theology, or by your own gut feelings and common sense, and do you think that most sane people, regardless of their religious or philosophical conditions, would probably tend to draw the same conclusions?
Does more need to be said about Loki?