Pope Francis bends over to kiss a small child as he arrives at Independence Mall where he was to deliver remarks on the theme "We Hold These Truths," a quote from the U.S. Declaration of Independence, in front of Independence Hall in Philadelphia, Sept. 26 2015. Reuters/Jim Bourg

For his final event in the U.S., Pope Francis celebrated Mass with hundreds of thousands in the streets of Philadelphia Sunday, stating in his sermon that faith is often shown in small acts of gratitude, kindness and compassion. The Mass marked the end of his six-day trip to the U.S. during which millions of people camped out to catch a glimpse of him.

"Holiness is tied to little gestures. Love is shown by little things," Pope Francis said in his sermon Sunday, according to the Huffington Post. "Faith grows when it is lived and shaped by love."

During his sermon the pope, again emphasizing the need for everyone in attendance to think small, said faith should begin with family.

"Our families -- our homes -- are true domestic churches. They are the right place for faith to become life and life to become faith," Pope Francis said, adding that God accepts all different kinds of families. "Anyone who wants to bring into this world a family which teaches children to be excited by every gesture aimed at overcoming evil ... will encounter our gratitude and our appreciation -- whatever the family, people, region or religion to which they belong!"

An official head count was not immediately available. Church officials had said previously that they were expecting up to 1 million people to attend the Mass. The Archdiocese of Philadelphia ordered hundreds of thousands of communion wafers and had 1,500 priests and deacons ready to distribute them, according to the Huffington Post. People posted pictures on social media of the scene the night before, when tens of thousands were camping out for the event.

Before the Mass, Pope Francis made an unscheduled stop at St. Joseph’s University, a Jesuit school, and blessed a new statue dedicated to ties between Catholics and Jews.

He then visited the St. Charles Borromeo Seminary, where he met with five victims of sexual abuse, speaking with them individually and as a group, and praying with them.

Pope Francis also visited the Curran-Fromhold Correctional Facility, where he told the inmates, "All of us have something we need to be cleansed of."

“I am here as a pastor, but above all as a brother, to share your situation and to make it my own,” the pontiff told the roughly 100 male and female detainees. “Jesus doesn’t ask us where we’ve been, and he doesn’t ask us what we’ve done."

Pope Francis is scheduled to fly back to Rome at 8 p.m. and will be sent off by a delegation that will include Vice President Joseph Biden, the New York Times reported.