We have Jesus’ universal mission Matthew 28:18-20 “Then Jesus came to them and said, "All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age." Great Commission and Mark 16:15 “He said to them, "Go into all the world and preach the good news to all creation.” The fundamental role of the church is to find those who are lost, preach the gospel to those people, and turn them into Jesus Christ’s disciples to further preach his gospels.
Additionally, as Matthew22:37-39, it is to follow the Great Command. To summarize, it is the mission of the church to make all people disciples of Jesus Christ and to love God and neighbor.