 -- Pope Francis had a piece of advice for the Americans he spoke to during a virtual audience hosted by ABC News: “Be courageous.”

During the event, which was moderated by ABC News’ "World News Tonight" anchor David Muir on Monday, the pontiff spoke for nearly an hour via satellite from the Vatican with individuals from the Cristo Rey Jesuit High School in Chicago’s inner city, congregants from Sacred Heart Church in McAllen, Texas, located near the U.S.-Mexico border, and homeless men and women and those working with the homeless in Los Angeles.

The three locations were selected by ABC News because they are in parts of the country that Pope Francis will not be visiting during his historic trip to the United States, later this month.

The selected speakers, which included an undocumented teenager who had lost a soccer scholarship to college and a homeless mother of two, were all people who had struggled with adversity. The speakers were told beforehand they would get to share their story with his Holiness.

Throughout the hour-long event, Pope Francis consoled the speakers, many of whom shed tears as the Pontiff offered them words of praise, encouragement and advice.

“It’s true that there are difficulties on life’s path, many of them,” the Holy Father said. “Don’t fear the difficulties. Be prudent, be careful, but don’t fear.”

One of the most powerful moments during the event was when Valerie Herrera, 17, stepped up to speak.

Herrera, a senior at the Cristo Rey Jesuit High School, told Pope Francis she had struggled with vitiligo, an autoimmune disease that causes white blotches on the face and body, and had endured bullying through elementary and middle school.

Herrera, the eldest of four children born to parents from Mexico, said she sang in her church choir and had found comfort through music.

In her question, she asked what the Holy Father expects from today’s youth and what should they aspire to be.

But before he answered her question, Pope Francis surprised Herrera with a request.

"May I ask for you to sing a song for me?" he said in English. As Herrera hesitated, Pope Francis told her, “be courageous."

After a long pause and encouragement from the audience, Herrera sang, "Junto a Ti Maria (Next to You, Maria)."

When the applause died down, Pope Francis answered her question.

“What I hope for from youth is for you all not to walk alone in life,” he said. “Life is very difficult. It’s difficult to walk alone. You get lost. You get confused. You can find the wrong path or you can be walking around in circles, in a maze, or worst, you can stop because you get tired of walking in life. Always walk hand-in-hand with someone who loves you, someone who gives you tenderness.”

“In my country, there’s a saying, 'it’s better to be alone than to be in bad company,'” continued Francis, who is from Argentina. “That’s true, but walk accompanied... You have the strength to overcome. Don't be scared. Don't stop. There's nothing worse than a young person who has retired before his or her time. I don't know at what age people retire in the United States, but can you imagine a young person who's 25 years old, who's retired? Terrible. Always move forward with courage and with hope."

The pope praised Rosemary Farfan, 31, for caring for her two young daughters by herself. The family had been living at the Good Shepherd Center for Homeless Women and Children, a program of Catholic Charities of Los Angeles, but left in June to move into their first apartment.

“I know it’s not easy to be a single mother,” Francis said. “I know that people can sometimes look askance at you, but I’ll tell you one thing, you’re a brave woman because you’re capable of bringing these two daughters into the world.”

"You could have killed them inside your womb, and you respected life," the pope continued. "You respected the life you were carrying inside you, and God is going to reward you for that, and he does reward you for that. Don't be ashamed. Hold your head high. 'I didn't kill my daughters. I brought them into the world.' I congratulate you. I congratulate you, and God bless you."

Hundreds gathered at Sacred Heart Church in McAllen, Texas, including Ricardo Ortiz, 19, who told Pope Francis that he had come to the U.S. from Mexico on a tourist visa when he was 4 years old. He said his father sometimes had difficulty finding work because he was undocumented. Then when Ortiz was around 17, he said his father had an accident and wasn’t able to work at all.

Choking back tears, Ortiz, who has three younger brothers, said, "That happening impacted my life in a very deep way. I had to become the breadwinner of the family. I had to be the person that supported our family... I never lost faith. I never lost the strength that my father and mother gave me."

Ortiz told the pope that eventually his father was able to return to work and Ortiz was able to graduate high school. He had even won a soccer scholarship to college, but the scholarship was revoked once the school discovered he was not a U.S. citizen. His father scraped together the money to send him to a community college instead.

Pope Francis, an avid soccer fan, expressed admiration for Ortiz and told him that "the match is played between friendship in society and enmity in society."

"We are all created for friendship in society. All of us bear responsibility for everyone else," the pope said. "And each one has to make a choice in his or her heart. And we have to help that choice to be made in the heart. .... Only closeness and giving of myself, all that I have to give, the way you gave everything you could as a boy, when you supported your family. Don't forget that."

Another surprising moment during the event is when the pope called out directly to Sister Norma Pimentel, the executive director of Catholic Charities of the Rio Grande Valley. Sister Pimentel runs a welcome center at Sacred Heart Church in response to the surge of immigrants being released by the U.S. border patrol. More than 23,000 immigrants have passed through the center.

The Holy Father singled Pimentel out in the audience and called her to the front.

“I want to thank you, and through you to thank all the sisters of religious orders in the U.S. for the work that you have done and that you do in the United States," the pope said. "It's great. I congratulate you. Be courageous. Move forward. Take the lead, always. I'll tell you one other thing. Is it inappropriate for the Pope to say this? I love you all very much."

The virtual audience was conducted ahead of Pope Francis' upcoming visit to the United States, when he will travel to Washington, D.C., New York City and Philadelphia from Sept. 22 to Sept. 27.

When Marcus Alston, a 19-year-old who had lived on the streets of Los Angeles and on Monday was staying at Covenant House, asked the pope why his upcoming trip to the US was important, the Pontiff said he wanted to connect to Americans.

“There’s something very important for me, which is closeness,” Francis said. “For me it's difficult not to be close to people. When I approach people, as I'm going to do with you, it's easier for me to understand them and help them along life's path. That's why this trip is so important, for me to draw close to your path and your history.”