The text, titled One in Christ, United in Mission, was signed by the Pope on January 25, 2026, the feast of the Conversion of the Apostle Saint Paul. In it, Leo XIV urges the entire Church to continue the missionary journey after the Jubilee Year. According to the Pope, that journey requires “hearts united in Christ, reconciled communities” and a willingness to collaborate “with generosity and trust.”
The Pontiff places union with Christ at the center of the mission and begins with Jesus’ prayer recorded in Jn 17:21: “That they may all be one […] so that the world may believe that you have sent me.” From that union, he explains, spring the communion among believers and all missionary fruitfulness. For this reason, he affirms that the Church’s first missionary responsibility is to keep unity alive among its members.
“There is no true evangelization” without the proclamation of Christ
Alongside his insistence on unity, Leo XIV underlines what the content of the proclamation must be. He takes up the words of Saint Paul, “we do not preach ourselves, but Christ Jesus as Lord.” He then quotes Saint Paul VI in Evangelii nuntiandi: “There is no true evangelization unless the name, the teaching, the life, the promises, the Kingdom, the mystery of Jesus of Nazareth, the Son of God, are proclaimed.”
The Pope clarifies that missionary unity “must not be understood as uniformity,” but as the convergence of different charisms toward the same end. In his view, evangelization takes place when cultural, spiritual, and liturgical differences are expressed harmoniously “in the same faith.” He also calls for overcoming “factional divisions” among the followers of the one Lord and refers to Saint Paul’s letter to the Corinthians (1 Cor 1:10-12).
One hundred years since Pius XI’s decision
The text recalls that Pius XI instituted the Day in 1926 at the proposal of the Society for the Propagation of the Faith, which continues to distribute the collections in the Pope’s name. Leo XIV thanks the service of the Pontifical Mission Societies, which, he writes, he experienced during his ministry in Peru. There are four: the Society for the Propagation of the Faith, the Missionary Childhood, Saint Peter the Apostle, and the Missionary Union. The Pope also dedicates a recognition to the Pontifical Missionary Union, founded in 1916 by Blessed Paolo Manna, on its 110th anniversary.
The final section is dedicated to the ad gentes missionaries, whom the Pope compares to Saint Francis Xavier for having left behind land, family, and security. He asks for prayer for new missionary vocations. He evokes Saint Francis of Assisi on the eighth centenary of his death and Saint Thérèse of the Child Jesus. The message concludes with a prayer and a call to support the missions, because “every gift, however small,” becomes an act of missionary communion.
In Spain, the official DOMUND website presents the centenary with three slogans: “100 years with you,” “100 years for them,” and “100 years for Him.” The last one refers to Christ as “the first missionary.”