Missionary activity of the Catholic Church is considered as a fulfillment of the last commandment left by Jesus Christ to his disciples after his Resurrection. This commandment is faithfully carried out through the centuries of the Church’s existence. The paper, which is divided into two main parts, is tasked to present the modern emphasis of the Church's teachings starting from the documents of the Second Vatican Council throughout the documents and the messages of Pope Benedict XVI that are directed to the missionaries around the world. At the beginning of the thesis author defines the meaning of the terms mission and vocation, which is important because the vocation is related to the invisible existence and activity of the Holy Trinity within the Church, through which the Church’s visible activity is manifested, especially within the missionary activities around the world. The documents of the Catholic Church emphasize the threefold dimension of the Jesus Christ; the prophetic, royal and priestly. The educational dimension of the Catholic Church to the faithful should be directed both ad extra and ad intra. The second main part of the paper presents all of the messages sent by the Pope Benedict XVI for the World Mission Day. These messages have great theological importance because they describe the ecclesiological and Christological dimensions of preaching the Good News to the people around the world, not in the domineering manner but gently and with hope in Jesus’s words of salvation to all people.