Pope Francis, facing simultaneous clergy sexual abuse crises in several countries, on Monday wrote an unprecedented letter to all the world’s Catholics. The pontiff promised that no effort will be spared to prevent abuse and its cover up, Reuters said. The letter also responded to a recent grand jury report in the US state of Pennsylvania. The pope said that while most cases in the report “belong to the past,” it was clear that abuse “was long ignored, kept quiet or silenced.”