Doesn't it say somewhere that God is the judge? And he will take any vengeance that needs be?
God is the ultimate Judge, but He set up a system here on earth for judging (part of His commands to Moses), and a lot of our laws descend directly from that Law. So, we are to judge, but fairly.
As for vengeance, that's what we're supposed to avoid. He will avenge. But that doesn't preclude punishment, also clearly set up in the Law God gave Moses.
The New Testament verse, "Judge not, lest you be judged" is probably the most often quoted and misunderstood verse in Scripture, and is used to excuse all sorts of bad behavior. Jesus never told us not to assess wrongdoing, and He never undid Old Testament Law. He came to fulfill it.
My wheels kind of come off, with all the tough talk coming from people that on one hand claim to hold the answers about all matters of morality, and then spout off in ways which makes me wonder if they should hold sway over my opinions, whatsoever?
"Vengeance is mine...." and... Life in prison without chance for release, being the ultimate punishment for somebody that wants to die for his religion.
I completely agree that some of the comments are over the top, and uncalled for. Within our judicial system, Tsarnaev deserves the death penalty (which I think should be used exceedingly sparingly). If he gets a life sentence (depending on how it is treated), it may also be an appropriate sentencing, but not as appropriate as putting him to death.
None of that is inconsistent with Christianity, but the revenge aspect of the comments here definitely are.
I do agree with those who say that not all the victims desire leniency for this monster. And I would tend to think that more of them want this terrorist punished to the max.
They're just not getting all the attention.