Living the “Gospel of Life” requires sacrifice but God is infinitely generous in return, the secretary to the Apostolic Nunciature to the U.S. told youth at the Mass for Life in Washington, D.C. on Friday.

“To be a witness to the Gospel of Life, we have to give back our life to the One to Whom it belongs,” said Father Daniele Rebeggiani, a Washington archdiocesan priest and secretary to the Apostolic Nunciature to the U.S. and the homilist for the Mass for Life celebrated at Capital One Arena in Washington, D.C. on Friday. The Mass preceded the 47th annual March for Life, expected to attract nearly 100,000 people from across the U.S. and foreign countries.

Fr. Rebeggiani preached on the Gospel for the Mass, the story of the rich young man who left Christ sad because his “heart was divided.”

“This Mass is an invitation to all of us to leave everything, to abandon our life totally to the Lord,” Rebeggiani said, inviting those present to ask a priest if they “ever regretted living a life of celibacy” or their parents if “they’ve ever regretted their sleepless hours.”

In order to be a witness to the gift of life, “we should be willing to undergo some persecution,” he said. Yet, he said, “the Lord will never, ever disappoint you,” and “I have never, ever regretted giving my life to the Lord.”

The Mass, preceded by a youth rally, was attended by an estimated 18,000 teenagers and young adults from more than 50 dioceses around the country just hours before the March for Life was set to begin on the National Mall.

The March for Life is held each year on or around the anniversary of the Supreme Court’s Jan. 22, 1973 Roe v. Wade decision that overturned state abortion bans and legalized abortion nationwide in cases before the unborn baby is “viable.”

On Friday morning, Archbishop Wilton Gregory of Washington, D.C. celebrated the Mass for Life, with the Apostolic Nuncio to the U.S., Archbishop Christophe Pierre, concelebrating along with more than 180  bishops and priests.

Archbishop Pierre greeted those present at the beginning of the Mass and thanked them on behalf of Pope Francis for “showing your solidarity with the unborn in the ‘throwaway culture’.”

“We don’t fight for an idea. We fight for the future of the human being,” Pierre said.

The nuncio cited Pope Francis’ comparison of abortion to hiring a hitman to kill someone, saying “never, never eliminate a human life or hire a killer to solve a problem. Abortion is never the answer that women and families are looking for.”

“The Holy Father is close to you, and believes in you, and with his spirit he marches with you,” he said.

The Youth Rally and Mass for Life is the largest annual event of the Archdiocese of Washington. It precedes the March for Life, attended annually by tens of thousands of pro-life advocates from all over the U.S. and internationally.

Friday’s rally and Mass carried the theme of “Living the Gospel of Life,” taken from the “life in abundance” promised by Christ in the Gospel of John, chapter 10, in answer to the culture of death which promotes abortion.

At the rally preceding Friday’s Mass, abortion survivor Melissa Ohden told her story to the audience. Two religious sisters—Sister Josephine Garrett of the Holy Family of Nazareth, and Sister Maria Juan Anderson of the Religious Sisters of Mercy—addressed the youth, and Catholic singer Sarah Kroger performed.