All baptized Christians are challenged to spread the Gospel, no matter their state in life.
It is tempting to think of “missionaries” as only those heroic priests or religious in far away lands, bringing the Gospel to native tribes. While that may be true definition of the word, it is only part of the picture.
In reality, all baptized Christians are challenged to become missionaries in their everyday lives.
St. John Paul II reiterated this point during a homily in 1998.
Baptism is also a source of apostolic dynamism. The missionary task of the baptized, in conformity with their own vocation, is extensively considered by the Council which, in the Constitution Lumen gentium, teaches: “Each disciple of Christ has the obligation of spreading the faith to the best of his ability” (n. 17). In the Encyclical Redemptoris missio, I stressed that by virtue of Baptism all lay people are missionaries (cf. n. 71).
Even the Catechism of the Catholic Church confirms this “missionary mandate.”
“Reborn as sons of God, [the baptized] must profess before men the faith they have received from God through the Church” and participate in the apostolic and missionary activity of the People of God. (CCC 1270)
What this means is that lay people are not somehow exempt from preaching the Gospel to other people. This does not entail, however, standing on every street corner and asking everyone you see if they are a Christian.
Being a missionary can take multiple forms, always in accord with a person’s state in life.
It could entail delivering the Good News to people you have never met before, but most of the time, it revolves around the living of an authentic Christian life.
The baptismal seal enables and commits Christians to … exercise their baptismal priesthood by the witness of holy lives and practical charity. (CCC 1273)
The world should be able to easily identify you as a Christian by the way of your life and the words you speak or write on social media.
In this way, all baptized Christians can be missionaries, preaching the Gospel with words, but most of all, by their way of life.