In February 2016, while on his way home following a visit to Mexico, Pope Francis said the following when asked about Trump:

A person who thinks only about building walls—wherever they may be—and not building bridges, is not Christian. …I’d just say that this man [Trump] is not Christian if he said it this way. …We must see if he said things in that way and in this I give the benefit of the doubt.

Trump responded that it was “disgraceful” for the Pope to question his faith, suggesting that the Mexican government was “using the Pope as a pawn” for political purposes, “because they want to continue to rip off the United States.”Trump added that “if and when” Islamic State attacks the Vatican, the Pope would have “wished and prayed” Trump were President because under his leadership such an attack would not happen.

The following day, Director of the Holy See Press Office Federico Lombardi insisted that the Pope was not launching an attack on Trump nor trying to sway voters by declaring that someone who advocates building walls is not Christian. After the clarification by Lombardi, Trump downplayed his differences with the Pope, saying “I don’t think this is a fight.”

(Resource Wikipedia)