BOSTON -- "Intrigued." That is how Mark K. Shriver, president of the Save the Children Action Network, said he felt as he watched Jorge Mario Bergoglio become Pope Francis in March 2013.

"His first couple of actions -- from asking for blessings from the people before he blessed them as the new pope, to paying for his hotel bill, to washing the feet of those young juvenile delinquents at the Casa del Marmo -- really caught my eye," he recalled.

"Seeing all these early actions of his made me question, 'Is he for real, or is this some kind of public relations stunt?'" Shriver said.

Seeking the answer to this question, Shriver embarked on a two-year journey in which he found himself travelling to Buenos Aires, reading Pope Francis' homilies, speaking to countless friends and acquaintances -- Catholic and non-Catholic alike. The result is his book, "Pilgrimage: My Search for the Real Pope Francis," released Nov. 29, that explores the life of Jorge Bergoglio through the eyes of many of his closest friends.

"After immersing myself in Pope Francis -- in his life, in his actions, in his words -- I can very much say he is the real deal," Shriver said.

"(Pope Francis) was washing people's feet in the villas of Buenos Aires, not just on Holy Thursday, not just when the cameras were on, but always," he said. "He has been reaching out to those on the periphery in Buenos Aires for a very, very long time."

This week, Shriver travelled to Boston from his Maryland home, for the release of his book.

"I wanted to be in Boston for the book release because Cardinal Seán P. O'Malley has been very helpful to me throughout this process," he explained, adding "I have great admiration for Cardinal O'Malley and his work among the poor."

According to Shriver, the book depicts Pope Francis through the eyes of those who knew him before he was made pontiff.

"Through the eyes of rabbis, of priests, of mothers who have lost their children, of workers on the fringes of society -- they tell the story of who Jorge Bergoglio is to them," he explained. "This book is for anybody looking to deepen their knowledge of Pope Francis, but also for anyone looking to deepen their relationship with God in general."

In writing the book, Shriver said his own relationship with God has evolved. A cradle Catholic who attended a Jesuit high school in Maryland and graduated from Holy Cross College in Worcester, Shriver believes his two-year journey has deepened his relationship with God.

"(Pope Francis') words and actions challenge me to get my shoes muddy, to get much more involved in the lives of others -- which is a good challenge to have," added Shriver.

"He has made me look at my life differently," he said. "On some level he's made me more aware and more attuned to the concept of mercy."

Shriver admitted that when he first considered the idea of mercy, he likened it to "being nicer to people."

"But Francis' vision of mercy is much more. It is to really interact with the pain and the chaos, -- as well as the joy -- of other people's lives," he explained. "You don't just write a check, or serve the poor. You walk with them."

Shriver is no stranger to service. His father, Sargent Shriver, founded the Peace Corps in 1961 and served as its first director. His mother, Eunice Kennedy Shriver, founded the Special Olympics. And yet, he noted that Pope Francis "has challenged me to my core."

"For Pope Francis, it's a two-way street -- you reach out and help them, but just as importantly, they help you by how they live their lives, by having you get involved in their lives," Shriver said.

"I don't manage to do it every time," he said. "I'm trying. I guess I'm still a pilgrim."

In speaking to Pope Francis' friends, Shriver said he also was struck by the pontiff's humility and faith.

"This guy's life is incredibly humble," he said. "He teaches me about humility. He teaches me about faith. He teaches me about mercy. He teaches me to do what is right, not what is expected."

"Pope Francis isn't a conservative; he isn't a liberal. He can't easily be put into some box, or some label -- he clearly wants to do what his boss wants him to do -- and his boss is Jesus Christ," he said.