The Church advances when it preaches the Gospel and teaches what Jesus said and did to the lost outside the building. Of course this is called the Great Commission.
Jesus says in:
18 And Jesus came up and spoke to them, saying, “All authority in heaven and on earth has been given to Me. 19 Go, therefore, and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit, 20 teaching them to follow all that I commanded you; and behold, I am with you always, to the end of the age.”
15 And He said to them, “Go into all the world and preach the gospel to all creation. 16 The one who has believed and has been baptized will be saved; but the one who has not believed will be condemned.
Luke 24: 45-47
45 Then He opened their minds to understand the Scriptures, 46 and He said to them, “So it is written, that the Christ would suffer and rise from the dead on the third day, 47 and that repentance for forgiveness of sins would be proclaimed in His name to all the nations, beginning from Jerusalem.
So we see the definitive command by the Lord who had by then had been crucified, buried, raised from the dead and shown Himself to His disciples for 40 days to go into all the world with the message about Himself.
Do you believe He intended for the message to fail?
Do you believe He intended for the message to be kept to ourselves?
The message is what moves the church forward or better said the church increases the number of believers and expands its territory when it preaches the Gospel and disciples the nations.
Therefore the reverse is true: if the church does not preach the Gospel and disciple the nations it will not expand its territory or increase in numbers.
What must the church always be doing: preaching he Gospel to unbelievers and teaching them the teachings of the Lord. When this happens the church will advance.