I don't think that we can say that there is one point to Julius Caesar. To boil things down to one or even two points is probably to misread or misunderstand Caesar. What makes Caesar so interesting is that many things resonate with people. Let me give you a few points to ponder. First, there is the notion of freedom and fighting for freedom, no matter what the cost is. From this perspective Brutus and his friends can be seen in a heroic light. Second, there is the idea of ambition. Caesar forces you to think about how much is too much. Did he go too far? Third, Caesar also forces you to think about honor and friendship. To what extent will you go to be loyal? Finally, Caesar also forces you to think about models of leadership and the relationship between people of power and the state.
I assume you mean what are the meanings or themes of Shakespeare's play, Julius Caesar, or what is revealed about human existence in the play. With that in mind, the following themes and principal topics are analyzed in the enotes Study Guide on the play:
- Depiction of Roman Politics
- Private and Public Values of Brutus and Cassius and the relationship of human endeavor and history
Those are some of the larger issues reflected in the play. Of course, though, entertainment is always a central purpose in art. If you were actually asking about what is the point of reading the play, entertainment, enlightenment, insight, and knowledge might be reasons to read it.