A mysterious group that calls itself "Christian State'' has threatened to kill Muslims and destroy their establishments in Belgium, apparently in retaliation to the Islamic State (ISIS) attacks in Paris that killed 130 people on Nov. 13. The warning was written in a letter delivered last week to the Attadamoune mosque in Molenbeek, Belgium, according to French and Belgian media reports. "No mosque and none of your businesses will be safe,'' and "brothers [Muslims] will be slaughtered like pigs and crucified as our Lord converts their souls,'' the group said in the letter that was found in the mosque's mailbox...