The Great Commission

Matthew 28: 16 – 20 (NIV): Then the eleven disciples went to Galilee, to the mountain where Jesus had told them to go. When they saw him, they worshiped him; but some doubted. 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."

This mountainside may have been the same one where he preached the Sermon on the Mount in Matthew 5 and where he fed the five thousand people with the five loaves and two fish. It happened after Jesus fed them breakfast on the beach, but before his ascension forty days after his resurrection. Matthew tells us the eleven remaining disciples were there, but there may have been as many as five hundred other people present as well. Paul says in 1 Corinthians 15:6 that five hundred people saw Jesus at some point after his resurrection. This easily could have been that occasion. The townspeople saw the disciples going to the hillside and, as word spread, everyone joined them to see what was going on.
Another hint to this is that Matthew said “some doubted.” There is no reason to believe he meant any of the eleven disciples, although we cannot be sure.
Jesus gave the crowd their marching orders: to spread the good news and teach believers to obey his word. He earned the right to give this commission when he rose from the dead. Think about it, if the early believers hadn't spread the news, we wouldn't know about Jesus today. But they did. They told and they taught and the church is thriving today because of it, two thousand years later and all over the planet.
Jesus told them to baptize in the name of the Father, Son and Holy Spirit, a clear indication of the Trinity. And he told them to teach people to become disciples – learners – after they hear about him. The more we learn, the more we can spread the correct Gospel.
Finally, Jesus encouraged them that they wouldn't have to do this alone. He would be with them and all who believed because of their testimony. He would provide the power needed to build his church. He would provide the courage to follow and obey him. This Great Commission still stands today as our instructions from the Master. Now, it's our turn to obey it.