If that’s true, then the Les Mis “Arena Concert Spectacular,” concluding its two-year world tour now through August 9 at Radio City Music Hall, is about as close to a religious experience as musical theater can get. It’s Les Mis, Encores! Barks, who played Éponine in Tom Hooper’s motion picture, is a glowing Fantine whose smile isn’t even dimmed by death. Given the precarious state of theatrical economics these days, we may not see a Les Misérables of this scale again for a long time. In short, it’s everything Les Mis should be.