There is a wonderful saying ‘Begin with the end in mind.’ When starting to compose your speech, it is best to start with the close.
The close is the end of the journey. If you do not have a specific destination, you can wind up anywhere and will not only lose yourself. you audience will wind up who know where. With the destination in mind you can now build an effective opening that sets the tempo and path to the final destination.
Whether it is a strong moral, call to action or critical learning point, the close is the message in a nutshell. Everything else is just supporting information to support the message.