Just as God's will is creation and is called "the world," so his intention is the salvation of men, and it is called "the Church." 155
Catechism number 767
"When the work which the Father gave the Son to do on earth was accomplished, the Holy Spirit was sent on the day of Pentecost in order that he might continually sanctify the Church."174 Then "the Church was openly displayed to the crowds and the spread of the Gospel among the nations, through preaching, was begun."175 As the "convocation" of all men for salvation, the Church in her very nature is missionary, sent by Christ to all the nations to make disciples of them.176