Pope Leo XIV: ‘One in Christ’ is key to the Church’s mission

Pope Leo XIV has set “One in Christ, United in Mission” as the theme for World Mission Day 2026, marking the 100th anniversary of the annual celebration established by Pope Pius XI.

In his message, released Jan. 25 on the feast of the Conversion of St. Paul, the pope writes that the Church’s missionary renewal depends first on spiritual communion and reconciliation within Christian communities.

“The mystery of union with Christ lies at the heart of mission,” Leo writes, warning that “conflicts, polarization, misunderstandings, and a lack of mutual trust” can erode the Church’s witness when they take root “even within our communities.”

World Mission Day will be observed Oct. 18.

Union with Christ and unity among Christians

Reflecting on the call to evangelize after the jubilee year, the pope writes that the missionary path “requires hearts united in Christ, reconciled communities and, in everyone, a willingness to cooperate with generosity and trust.”

Leo also links the theme to ecumenical efforts, encouraging Catholics to deepen engagement with other Christians “building upon the opportunities arising from the joint celebration of the 1,700th anniversary of the Council of Nicaea.”

He stresses that the Christian life is not reducible to an ethical code or a set of ideas.

“Being a Christian is not primarily about practices or ideas; it is a life in union with Christ,” he writes, adding that this communion “is the source of all missionary fruitfulness.”

‘Not an end in itself’

The pope emphasizes that unity is ordered toward proclamation of the Gospel.

“The unity of disciples is not an end in itself; it is directed towards mission,” Leo writes. “It is through the witness of a reconciled, fraternal, and united community that the proclamation of the Gospel acquires its full communicative power.”

He recalls the motto of Blessed Paolo Manna — “All the Churches United for the Conversion of the Whole World” — and notes the 110th anniversary of the Pontifical Missionary Union, founded in 1916. “No baptized person is exempt from or indifferent to mission,” he writes.

Thanks to the Pontifical Mission Societies

Leo offers specific thanks to the Pontifical Mission Societies, writing that their work supporting missionary cooperation is something “I experienced with gratitude during my ministry in Peru.”

He points to their efforts to “promote a network of prayer and charity that connects communities throughout the world” and recalls the role of Blessed Pauline Marie Jaricot, founder of the Society for the Propagation of the Faith, who established the living rosary.

The pope also highlights the origins of World Mission Day itself, noting that Pius XI established it in 1926 following a proposal from the Society for the Propagation of the Faith and that the annual offerings gathered are distributed “on behalf of the pope” for the Church’s missionary needs.

Mission as a work of love

In the final section, Leo frames mission as an outgrowth of God’s faithful love revealed in Jesus Christ.

“If unity is the condition of mission, love is its essence,” he writes. “The good news that we are sent to proclaim to the world is not an abstract ideal; it is the Gospel of God’s faithful love, which became flesh in the face and life of Jesus Christ.”

He expresses gratitude to today’s ad gentes missionaries — those sent beyond their homelands — and appeals for new missionary vocations.

“The world still needs these courageous witnesses of Christ, and ecclesial communities still need new missionary vocations,” he writes. “We must always keep them close to our hearts and continually pray to the Father for them.”

Citing St. Francis of Assisi, Leo acknowledges the challenges missionaries can face: “As St. Francis of Assisi said, ‘Love is not loved,’” he writes, urging Christians to let themselves be inspired by the saint’s desire to live and transmit the love of the Lord.

A prayer for unity and evangelization

Leo concludes with a prayer asking that believers be made “one in Christ,” strengthened for witness, and sustained in missionary service: “Holy Father, make us one in Christ, rooted in his love that unites and renews,” the pope prays, asking Mary, “Queen of Missions,” to accompany the Church’s evangelizing work “in every corner of the earth.”

This story was first published by ACI Stampa, the Italian-language sister service of EWTN News. It has been translated and adapted by EWTN News English.

Source: https://www.ewtnnews.com/vatican/pope-leo-xiv-one-in-christ-is-key-to-the-church-s-mission