On the occasion of the 100th World Mission Day, celebrated on 18 October 2026, I would like to offer the readers of www.comboni2000.org an attempt to retrace the development of the Church’s missionary awareness through a succession of documents on mission. I would even venture to invite readers to discern in them a common thread running through four centuries of history, beginning with the establishment of Propaganda Fide in 1622.
On the occasion of the 100th World Mission Day, celebrated on 18 October 2026, it is especially meaningful to reread not simply a succession of documents, but the evolution of the Church’s missionary consciousness. The Day was established by Pius XI in 1926, at the proposal of the Society for the Propagation of the Faith; for its centenary, Leo XIV chose the theme “One in Christ, united in mission.”
A selection of landmark documents
| Date | Document | Author | Contribution to the evolution of mission |
|---|---|---|---|
| 1659 | Instruction to the Apostolic Vicars | Propaganda Fide | Anticipates two ideas destined to become decisive: indigenous clergy and respect for cultures. Missionaries are not to export Europe, its customs or national identities, but the Gospel. It is an early intuition of inculturation. |
| 1919 | Maximum illud | Benedict XV | The great modern missionary turning point: it explicitly separates mission from nationalism and colonialism, insists on the formation of local clergy and presents mission as a universal responsibility of the Church. |
| 1922 | Romanorum Pontificum | Pius XI | Makes the Society for the Propagation of the Faith pontifical, strengthening a universal network of missionary cooperation. |
| 1926 | Rerum Ecclesiae | Pius XI | Advances the idea that the result of mission should not be permanent dependence on foreign missionaries, but the establishment of mature local Churches, with their own clergy and, progressively, their own episcopate. |
| 1926 | Establishment of World Mission Day | Pius XI | Mission ceases to be perceived as the task of a few specialized institutes: every diocese, parish and believer participates through prayer, vocations and solidarity. |
| 1951 | Evangelii Praecones | Pius XII | Deepens attention to the cultures of peoples and to the emergence of Churches fully rooted in their respective social and cultural settings. |
| 1957 | Fidei Donum | Pius XII | Introduces an ecclesiological turning point: established dioceses also send their own priests to other Churches. Mission becomes communion and an exchange of gifts among particular Churches. |
| 1959 | Princeps Pastorum | John XXIII | Brings the theme of local clergy and laity to maturity: young Churches are not simply territories assisted by the West, but responsible agents of evangelization. |
| 1964-65 | Lumen gentium + Ad gentes | Vatican II | The decisive turning point: mission is not a peripheral activity of the Church, because the Church is missionary by her very nature. Its origin lies in the mission of the Son and the Spirit within the Father’s plan. |
| 1965 | Nostra aetate | Vatican II | Places mission within a new relationship with religions: proclamation of Christ together with dialogue, respect and discernment of the seeds of truth present in religious traditions. |
| 1965 | Dignitatis humanae | Vatican II | Establishes a fundamental consequence for missionary practice: the act of faith must be free. Evangelization and coercion are incompatible. |
| 1965 | Gaudium et spes | Vatican II | Broadens the horizon: mission encounters the human person in history, culture, society, joys and sufferings. Evangelization involves dialogue with the world and service to humanity. |
| 1966 | Ecclesiae Sanctae | Paul VI | Translates Ad gentes into concrete ecclesial life: theology of mission in formation, diocesan responsibility, missionary cooperation and World Mission Day as an expression of the consciousness of the entire People of God. |
| 1975 | Evangelii nuntiandi | Paul VI | Gradually replaces the narrower paradigm of “missions” with the broader concept of evangelization: witness, explicit proclamation, personal conversion, transformation of cultures, human promotion and ecclesial community. |
| 1990 | Redemptoris missio | John Paul II | Reaffirms the permanent necessity of the missio ad gentes, distinguishing it from ordinary pastoral care and the new evangelization while situating it within the Church’s one mission. Strong emphasis on the Holy Spirit, the Kingdom, dialogue and inculturation. |
| 1991 | Dialogue and Proclamation | Pontifical Council for Interreligious Dialogue + Congregation for the Evangelization of Peoples | Clarifies that interreligious dialogue and proclamation are not alternatives: they are two authentic dimensions of the evangelizing mission, although they are not interchangeable. |
| 2013 | Evangelii gaudium | Francis | Places mission at the heart of every ecclesial reform: a “Church which goes forth,” missionary disciples, peripheries, pastoral conversion and a “permanent state of mission.” Mission is no longer the work merely of specialists: every baptized person is a missionary subject. |
| 2019 | Centenary of Maximum illud and Extraordinary Missionary Month | Francis | Recovers Maximum illud in order to relaunch a mission freed from political, economic and cultural interests: “Baptized and Sent” directly links baptism and mission. |
| 2022 | Praedicate Evangelium | Francis | Even the structure of the Curia is reread in a missionary key: the Dicastery for Evangelization is established and presided over directly by the Pope; evangelization and mission symbolically take a central position in the governance of the Church. |
| 2026 | “One in Christ, united in mission” | Leo XIV | On the centenary of World Mission Day, emphasizes mission as the fruit of communion in Christ, cooperation among Churches and charisms, the sharing of God’s love and the missionary responsibility of the entire People of God. |
1. The distant anticipation: Propaganda Fide and the Instruction of 1659
It is useful to begin well before 1926. Founded in 1622, the Sacred Congregation of Propaganda Fide also sought progressively to free missionary activity from dependence on the interests of European colonial powers. Perhaps the most striking text is the Instruction of 1659, addressed to the Apostolic Vicars in China and Indochina.
The Holy See itself describes it as a kind of “Magna Charta” of Propaganda Fide and highlights two elements: the promotion of local clergy and respect for cultures and traditions, except where these were contrary to faith and morals.
Here, in embryonic form, appears a distinction that would become central three centuries later: to evangelize ≠ to Westernize.
The missionary brings the Gospel, not the culture of his own homeland. This is the distant seed of what the twentieth century would call adaptation and, later, inculturation.
2. Maximum illud (1919): freeing mission from colonialism
The true modern watershed is Benedict XV’s apostolic letter Maximum illud, dated 30 November 1919. It was issued immediately after the First World War, when the connection between missionary activity and European colonial powers appeared particularly problematic.
Benedict XV insists on three changes:
- from national interest to the universal mission of the Church;
- from permanent foreign missionaries to the formation of indigenous clergy;
- from the work of individual institutes to universal ecclesial responsibility.
Missionaries are not to seek to extend the influence of their own nation. The goal, rather, is the birth of a Church capable of living with its own priests and structures. Benedict XV’s official Vatican biography likewise stresses the need to prepare an indigenous clergy capable of governing itself autonomously.
For this reason, Maximum illud can be regarded as the gateway to contemporary Catholic missiology.
3. Pius XI: from “foreign mission” to the establishment of local Churches
With Rerum Ecclesiae of 28 February 1926, Pius XI takes up Benedict XV’s legacy but goes a step further: mission must aim at the stable establishment of the Church among each people, rather than perpetuating a structure directed from outside.
That same year, something pastorally revolutionary took place. On 14 April 1926, at the request of the Society for the Propagation of the Faith, Pius XI approved the establishment of a Mission Day for the second-to-last Sunday of October throughout the Church.
The innovation was not merely financial. Through this Day, a new consciousness was fostered: the whole Church supports the mission of the whole Church.
Prayer, offerings, vocations and missionary awareness gradually transformed the relationship between the older Churches and those that were emerging.
4. Pius XII: from “missions” to young Churches
With Evangelii Praecones in 1951, Pius XII could already observe how much the situation had changed in the twenty-five years since Rerum Ecclesiae.
The perspective increasingly shifts from the simple conquest of new territories to the building of Christian communities embedded in local cultures.
Even more important is Fidei Donum of 1957. Pius XII states that every bishop, as a successor of the Apostles, bears responsibility for the Church’s mission beyond the boundaries of his own diocese.
From this arose the experience of fidei donum priests.
It marks a decisive change:
before: Europe “sends missionaries” to dependent territories;
now: one particular Church helps another particular Church.
In this way, the future conciliar ecclesiology of the communio Ecclesiarum begins to take shape.
5. John XXIII: when young Churches become protagonists
With the 1959 encyclical Princeps Pastorum, John XXIII brings the theme of local clergy and laity to maturity. Young Churches are no longer thought of merely as recipients of missionary activity, but as communities called to take full responsibility for their own life and for evangelization.
Particular attention is given to formation, so that priests, religious and laypeople can act in ways genuinely rooted in the culture and society of their respective peoples.
The decisive transition is therefore: from Churches assisted from outside to local Churches that are protagonists of mission.
This is one of the most immediate premises of the vision that the Second Vatican Council would develop a few years later in Ad gentes.
6. Vatican II: the ecclesiological revolution of Ad gentes
Here we find the deepest theological transition in the entire journey.
The Decree Ad gentes, promulgated on 7 December 1965, does not begin primarily with missionaries, works or territories. It begins with God.
The Church is sent because God himself is mission: the Father sends the Son; the Father and the Son send the Spirit; from this Trinitarian dynamic arises the sending of the Church.
Ad gentes accordingly defines the Church sent to the nations as the “universal sacrament of salvation.”
The change can be expressed in this way:
before: “the Church has missions”;
Vatican II: “the Church is missionary.”
This entails at least five consequences.
1) Mission as the nature of the Church
It is not a sector entrusted to specialized congregations. It is a constitutive dimension of the whole ecclesial community.
2) From plantatio Ecclesiae to the local Church
The aim is to bring into being fully ecclesial communities rooted in their own people, with their own ministries, charisms and forms of life.
3) Inculturation
The Gospel must take root in cultures, assuming what is authentic in them and purifying them from within.
4) Responsibility of all bishops and all Churches
Every particular Church participates in the universal mission.
5) Mission and witness
Proclamation cannot be separated from life, charity and service.
Significantly, Ad gentes also calls for a transformation of Propaganda Fide: not merely an administrative body, but a “dynamic directing body” capable of making use of contemporary theology, methodology and pastoral sciences.
7. The other conciliar documents also change the way mission is understood
Ad gentes cannot be considered in isolation.
Lumen gentium offers the new ecclesiology of the People of God: mission belongs to the entire people of the baptized, not only to clergy or religious.
Gaudium et spes introduces an attitude of dialogue with history and with humanity’s aspirations. Mission does not take place “outside” the world, but within the cultural and social transformations of human life.
Nostra aetate profoundly alters the relationship with other religions: Christians continue to proclaim Christ while recognizing, listening to and entering into dialogue with whatever is true and holy in other traditions.
Finally, Dignitatis humanae establishes an indispensable missionary criterion: faith cannot be imposed. Truth must be proposed by its own power, with respect for the dignity and freedom of the person. The Council explicitly states that no one may be forced to embrace the faith against his or her will.
This is the definitive theological overcoming of any confusion between evangelization, political power and coercion.
8. Paul VI: from “mission” to “evangelization”
With the 1966 motu proprio Ecclesiae Sanctae, Paul VI concretely implements Ad gentes. He asks that the theology of mission become part of theological formation and that World Mission Day express the shared responsibility of the whole People of God.
But the decisive document is Evangelii nuntiandi of 1975. Here a category broader than the traditional concept of mission comes to the fore: evangelization.
Evangelization includes together:
- the witness of life;
- the explicit proclamation of Jesus Christ;
- personal adherence;
- entry into the ecclesial community;
- the transformation of cultures;
- service and human promotion.
Paul VI explicitly links the exhortation to Vatican II and states that the Council’s fundamental intention can be understood as making the contemporary Church better able to proclaim the Gospel to contemporary humanity.
The question therefore changes from:
“Where are the mission territories?”
to:
“How can the Gospel reach and transform the human person and cultures?”
9. John Paul II: Redemptoris missio and the rebalancing of dialogue and proclamation
At the end of the 1980s a new question emerged: if all the Church’s activity is evangelization, does a specific mission ad gentes still exist?
John Paul II answers in the 1990 encyclical Redemptoris missio: yes. The mission of Christ entrusted to the Church is still far from completion, and missionary activity remains fully relevant.
The encyclical holds together several elements that risked being separated:
Christ, the one Savior — universal action of the Spirit — values present in cultures and religions — dialogue — inculturation — explicit proclamation — freedom of the person.
A more articulated understanding of the ecclesial landscape thus emerges:
- ordinary pastoral care, in living Christian communities;
- new evangelization, where faith has weakened;
- missio ad gentes, toward peoples and environments in which Christ is not yet truly known.
This distinction prevents the universal mission from being diluted into generic pastoral activity.
10. Interreligious dialogue and mission
An important stage is the 1991 document Dialogue and Proclamation, jointly prepared by the Pontifical Council for Interreligious Dialogue and the Congregation for the Evangelization of Peoples.
The theological point is delicate but decisive:
dialogue does not mean renouncing proclamation;
proclamation does not mean rejecting dialogue.
Both belong, in different ways, to the evangelizing mission. This is one of the most significant developments of the path opened by Nostra aetate, Ad gentes and Evangelii nuntiandi.
11. Francis: from the “mission of the Church” to a “Church which goes forth”
With Evangelii gaudium (2013), a further shift occurs.
Francis does not want mission to be simply one pastoral sector. He calls for a “missionary conversion” of the whole Church.
The best-known expression is “a Church which goes forth”: every Christian and every community is called to abandon self-referentiality and reach the peripheries.
The subject is no longer simply “the missionary,” but the: missionary disciple.
One is not first a disciple and then, perhaps, a missionary. Being reached by the Gospel generates the sending forth.
A long transformation is thus completed:
missionaries → missionary Churches → a missionary People of God → every baptized person a missionary disciple.
12. Even the Curia becomes symbolically “missionary”
The 2022 Apostolic Constitution Praedicate Evangelium establishes the Dicastery for Evangelization, which also brings together responsibilities historically linked to Propaganda Fide.
The symbolically highly significant fact is that the Dicastery for Evangelization is presided over directly by the Roman Pontiff.
From the Congregation founded in 1622, therefore, we arrive at a structure in which:
- first evangelization;
- new particular Churches;
- fundamental questions concerning evangelization in the world
are considered within a single missionary perspective.
12. The 2026 centenary: Leo XIV and mission as communion
Leo XIV’s message for the 100th World Mission Day, dated 25 January 2026, offers something close to a synthesis of the historical journey.
The theme is:
“One in Christ, united in mission”
The perspective emphasizes three aspects.
- Communion: unity in Christ precedes mission and makes it credible.
- Missionary synodality: charisms, communities and Churches work together, without unity meaning uniformity.
- Mission of love: the Good News is not primarily an abstract doctrine to be exported, but the faithful love of God manifested in Christ and shared through the lives of the disciples.
In the same message, Leo XIV significantly recalls that the Pontifical Mission Societies form a network of prayer and charity uniting communities throughout the world. One hundred years later, World Mission Day thus returns to its deepest meaning: making visible the universal missionary communion of the Church.
The common thread running through four centuries
If the development were to be summarized in eight transitions, it could be formulated as follows:
| From the conception… | …to the conception |
|---|---|
| mission also linked to European expansion | mission distinct from colonialism |
| European missionary as protagonist | local Church as protagonist |
| foreign clergy | indigenous clergy and episcopate |
| conversion sometimes accompanied by Westernization | inculturation of the Gospel |
| “mission territories” | particular Churches in communion |
| mission entrusted to specialists | responsibility of the whole People of God |
| proclamation understood mainly as preaching | evangelization as witness, proclamation, dialogue and service |
| a Church that “does mission” | a Church that is missionary and permanently “goes forth” |
There is, however, one element that does not change throughout this development: the conviction that mission arises from Christ’s sending and that the Church cannot renounce the proclamation of the Gospel. What changes profoundly is the understanding of the subject, the style, the recipients and the relationship between the Gospel, cultures, freedom and local Churches.
For this reason, the most significant trajectory can be condensed into the following sequence:
1659 – respect peoples →
1919 – free mission from nationalism →
1926 – involve the whole Church →
1957 – bring the Churches into missionary communion →
1965 – understand the Church herself as missionary →
1975 – conceive mission as integral evangelization →
1990 – reaffirm the enduring missio ad gentes →
2013 – make every baptized person a missionary disciple →
2026 – live mission as communion: “One in Christ, united in mission.”
The centenary, therefore, does not merely celebrate one hundred years of a missionary collection. It makes it possible to contemplate the transition from a mission conceived predominantly as the sending of missionaries to distant lands to a worldwide Church made up of local Churches that receive and give to one another the Gospel, people, charisms and resources, while remaining together responsible for proclaiming Christ to those who still do not know him.
