Through Baptism, "the Holy Spirit has placed in the heart and life of God, who is the communion of love," the pontiff said.
"God is a 'family' of three Persons who love each other so much they form a single thing."
Finally, Pope Francis turned to Mary, "the mirror of the Trinity, to reenforce our faith in the Trinitarian Mystery, and to embody it with choices and attitudes of love and unity."
After leading the crowds in the Angelus prayer, the Pope acknowledged the beatification of Francesco Maria Greco, diocesan priest, founder of the Sisters Little Workers of the Sacred Hearts.
"We give thanks to God for this exemplary priest," he said, to rounds of applause from the crowd. "This applause is for many good priests who are here in Italy!"
Pope Francis also mentioned the First World Humanitarian Summit, set to take commence in Istanbul on Monday.
The aim of the gathering is to look at measures needed to address "the dramatic humanitarian situations caused by conflicts, environmental problems and extreme poverty," the pontiff said.
"We accompany with prayer the participants at that meeting, in order that they may fully commit themselves to the principle humanitarian goal: saving the life of every human being, without exception, especially the innocent and the defenseless."
Pope Francis observed that Tuesday, May 24, the Catholics of China celebrate the Mary Help of Christians, who is venerated at the Shrine of Sheshan in Shanghai. Saying that "we will unite spiritually to the Catholic faithful in China," on that day, he asked Mary "to give to her children in China the ability to discern at all times the signs of the loving presence of God, who always welcomes always forgives."
"In this Year of Mercy, Chinese Catholics, along with those who follow other noble religious traditions, can become a concrete sign of love and reconciliation," the pontiff said. "In this way, they may promote an authentic culture of encounter and harmony of the whole society, the harmony that so loves the Chinese spirit."