Actually, we do have the right to judge which lives to take away. The bible was quite clear to the jews of the O.T. what behaviors warranted the death penalty (as it were). I don't recall the practice of putting people to death going away with Christ's arrival here. He came to fullfill the law, not abolish it. Though we would have a population crisis if we put all of the adulterer's to death, that does not mean that if we chose to do so - that it would be unbiblical.