ROME — Pope Francis called for greater openness to migrants Saturday, appealing for a change of narrative from the primacy of national security to the primacy of welcome. Addressing civil authorities on the first day of his visit to the island nation of Malta, the pontiff urged his hearers to open their hearts and “rediscover the beauty of serving our neighbors in need.” “Today, when those who cross the Mediterranean in search of salvation are met with fear and the narrative of ‘invasion’ and safeguarding one’s own security at any price seems to be the primary goal,” Francis said, “let...