The Pope has suggested
A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian,… This is not in the Gospel.
Pope Francis, long-critical of Trump's immigration policies, speaks out again during visit to Central America
In addition to the Pope, there was a recent NPR interview about the theological debate about the wall.
NPR's Michel Martin talks with Shaun Casey, director of Georgetown University's Berkley Center for Religion, Peace and World Affairs, about the theological debate over President Trump's proposed wall.
Meanwhile the White House pushes against the “immorality” of the wall.