As a child, Donald Trump attended Sunday school, he went with his parents to communion and was confirmed in a Presbyterian church in New York.
But his comments about Mexicans and his promise that, if elected president, he would make their government build a new border wall, prompted Pope Francis to doubt his Christianity.
Trump added in a statement; “No leader, especially a religious leader, should have the right to question another man's religion or faith.”
In the United States, faith plays an important role in the decisions of voters at the polls. A Pew Research Center survey published last month found Trump was considered the least religious among the major presidential candidates.
That perception could affect the election results: half of voters surveyed said they would be less inclined to vote for an atheist candidate. Among Republicans, nearly two-thirds said it was important that the president share their religious beliefs.
"This country always speaks as if it was discovered by God," said Arnoldo Torres, a political analyst and former director of the League of United Latin American Citizens (LULAC), a leading Hispanic advocacy group. "What the Pope said will generate an important discussion about how people can support a candidate who uses hateful language."
According to Torres, the Pope's words will also be used by Republican contenders against Trump. "Ted Cruz will use it, Marco Rubio will use it (...) Clearly they will discredit Trump," he predicted.
“I’m a Protestant”
In 2015, in a television interview on the Christian Broadcasting Network (CBN), Trump defined his faith. "I am a Protestant, I'm Presbyterian," he said. At that time he added that if elected president he would be “the greatest representative of the Christians they’ve had in a long time."
But Trump could be using religion for political ends, according to Daniel Alvarez, a theologian and professor of religious studies at Florida International University (FIU). "There is no religious substance. His attitude towards immigrants, Muslims do not reflect Christian values. Anyone can say they go to church," he said.
Not much is known about how the billionaire businessman practices his faith in private. He says he goes to church on Sundays, at Christmas and Easter, though some of his public acts have exposed him to criticism, including his change of stance on issues such as abortion in the heat of the presidential race.
During the Iowa caucuses in January, for example, Trump attended church with his wife and two staffers. When the silver communion plate reached Trump he pulled some dollar bills from his wallet instead of grabbing a wafer, according to the Associated Press. "I thought it was for the offering," he said, laughing.
In another event a week earlier, he gave a speech to 10,000 students of Liberty University in Virginia, and erroneously cited a passage from the Bible as "Two Corinthians" instead of the "Second Corinthians." That was despite his assurances that he owned several copies of the Bible. "I get sent Bibles by lots of people," he told CBN.
When interviewed in January by CNN’s Jake Tapper, Trump said "I don’t like to have to ask for forgiveness,” adding, “I try and do nothing that’s bad.”
Months earlier, a representative of the Marble Collegiate Church in New York denied Trump’s assertion that he was a frequent visitor. Asked about the subject in August 2015, spokeswoman Catherine Ortiz said that Trump was “not an active member” of the church.
On Thursday, Trump responded to questions about his faith again lining up another attack against Mexicans and their government. "They want to continue to harm the United States," he said.
Contacted Friday by Univision, the Trump campaign said that the candidate is a Presbyterian, and declined to discuss the matter further.