Pope Leo XIV on Sunday formally began his ministry as head of the 1.4 billion members of the universal Catholic Church, acknowledging divisions among the faithful with a call for fraternal communion and unity at his inaugural Mass.

Addressing an estimated 150,000 people crowded into St. Peter’s Square and the surrounding streets, the 69-year-old pope, elected May 8, said, “I would like that our first great desire be for a united Church, a sign of unity and communion, which becomes a leaven for a reconciled world.”

Under Pope Francis, the Church experienced internal division over issues of liturgy and moral doctrine on sexuality and the family, including the approval of the blessing of same-sex couples.

At the Mass, concelebrated with the members of the College of Cardinals, Leo expressed his intention to “come to you as a brother, who desires to be the servant of your faith and your joy, walking with you on the path of God’s love, for he wants us all to be united in one family.”