Matthew 28:16-20
16 Then the eleven disciples went to Galilee, to the mountain where Jesus had told them to go. 17 When they saw him, they worshiped him; but some doubted. 18 Then Jesus came to them and said, “All authority in heaven and on earth has been given to me. 19 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, 20 and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.”
Matthew 18:16-20 is known as the Great Commission and this is the second time I'm referring to it on this Site for the simple reason that it embodies the essence of the Gospel. These were the last words that Jesus in the flesh spoke to mankind before ascending to heaven. Jesus lets us know that HE is now in control and we are to follow His new covenant. Our works are to include the spreading of the gospel and then He reassures us that He will always be with us. Jesus is by our side till the very end of the age.
For me, this also signifies the start of the Christian church. Jesus' commission tells us to go and make disciples of all nations and to baptize all who willingly accept Him in the name of the Holy Triune. The early disciples did just that and the Body of Christ grew. Jesus didn't say go and build buildings and gather converts to them. The church is not wood and stone but the gathering of reborn souls unified in worship and obediance to our Lord and Savior.