The presidency is not the papacy. Most Catholics believe that when a pope is chosen, the man is changed by his ordination, transformed by the Holy Spirit into more than he has ever been. Americans do not have the same expectation of their presidents. They do not believe that the taking of the presidential oath does anything to change the person. They will be what they have always been. In fact, they are likely to be more of what they have been once they take office. This is why elections are often backward-looking affairs. We do not know the future and are just experiencing the present. The only way we can know if a man or a woman is qualified for the Oval Office is to look to their past.

When it comes to Donald Trump, this can be a disturbing experience. Whatever his gifts, he is a deeply imperfect man who has lived his life on a large scale. His deformities are obvious. The oddities of his personality frequently appear.

There is, for example, the now-famous episode of the speech he gave at his father’s funeral. Fred Trump, Donald’s father, died on June 25, 1999. The funeral was four days later. The 650 guests were treated to speeches by Reverend Arthur Caliandro, Norman Vincent Peale’s successor at the church, and by Rudolph Giuliani, mayor of New York. Then the Trump children spoke. Robert Trump said his father was his hero. Maryanne Trump, a federal judge, read a letter she had written to her father during her college days. Others spoke lovingly and movingly of the man.

When it was Donald’s turn, the topic was not what his father meant to him but rather what he meant to his father. He explained that he had heard of his father’s death after just reading a story in the New York Times extolling the success of one of his real estate projects, Trump Place. It reminded him that his father had always believed in him, that on this project as with the Grand Hyatt, Trump Tower, Trump Plaza, the Trump Taj Mahal, and Trump Castle, his father had known he would win and would always be a success.

On display was the familiar Donald Trump stronghold of self. Even at his own father’s funeral, he could not keep from promoting himself, from affirming himself — perhaps as a substitute for Fred Trump’s lack of affirmation. Yet that it was done publicly, unashamedly, before a solemn crowd and a grieving family, seemed brazen, even callous. This was the Donald Trump the world was beginning to know.

There are dozens of such stories from Donald Trump’s life, moments when he seems an unabashed force of self, incapable of viewing the world apart from his central role in it. This tells us much that we need to know. Whatever good he might bring to his presidency, he will also bring the soul of a successful man wrapped around the neediness of an unwisely fathered boy. It will make him haughty, pretentious, self-affirming, and often vicious when challenged.

He will need moral guardians around him, then. He will need the pastors and clergy and ministers of truth he so esteems. He does not keep friends for long and is not open to input from those he does not know and trust. He has an unusual regard, though, for those he perceives to speak for God, and these will need to be bolder and more pointed than they ever were during his campaign.

Excerpted from Choosing Donald Trump by Stephen Mansfield, published by Baker Books, a division of Baker Publishing Group. Copyright © 2017 by Stephen Mansfield. Used by permission.