In any public speaking class, you will be taught to end your message "with a bang"—with a strong conclusion. The end of your message tells the audience exactly what you want them to do with your speech.
It is interesting that the synoptic Gospels of Matthew, Mark and Luke all end with Christ giving admonition to preach the gospel. Mark records some of Jesus' last words on earth as, "Go into all the world and preach the gospel to every creature" (Mark 16:15). Some of Christ's last words in the book of Luke are recorded as, "Thus it is written . . . that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem" (Luke 24:46-47). Matthew's gospel ends with direct instruction to preach the gospel (Matthew 28:18-20). The book of Acts, which continues where Luke's Gospel ended, begins with instruction to preach the gospel "to the end of the earth" (Acts 1:8).
Obviously, Christ chose His parting words very wisely so we (as His followers) would know exactly what to do in His absence. UN