Remember that thing you just can't get over? Betrayal, tragedy, rejection—we've all experienced loss and injustice on a magnitude God never designed us for. Now that we've faced it, we're older, wiser . . . and rightly on guard against this fallen world. Or are we? Could it be that our cranky moods and critical words aren't just momentary lapses but evidence of a fatal poison creeping into our spiritual root system? Bitterness—the word...