What does Luke 19:19 mean?

The parable of the ten minas is an allegory for how Jesus will reward His followers when His kingdom is established on earth (Luke 19:11–27). He describes Himself as a nobleman who must leave to be crowned king of the territory he rules. The nobleman gives ten servants one mina each and orders them to invest it wisely and make him a profit. Later, the newly crowned king returns to his kingdom and calls his servants. How did they fare?

The first does an incredible job, making ten minas. The king grants him ten cities to rule over. This second servant also does very well. He took the one mina and made five. The king gives him authority over five cities.

Jesus tells this parable because the crowd He's surrounded by believes their march to Jerusalem for Passover will inaugurate Jesus' kingdom: His reign over the Jews. They don't understand He is marching toward His death on the cross, which is necessary for Him to be made King. Then He will have to leave for His coronation (Luke 24:50–53).

Until He returns, they need to take what He has given them—understanding that faith in Him saves—and invest it in other people. He's more explicit right before He ascends to heaven:

"But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth" (Acts 1:8).

Those who spread the gospel will be rewarded.