I need a thesis statement for Romeo and Juliet that revolves around the theme of hatred.

There are, as suggested by Shaketeach, a number of
approaches to take.

There is hatred on a personal level,
especially Tybalt's hatred for the Montagues and, specifically Romeo.  A thesis
statement exploring this hatred might be:  "In the play Romeo
and Juliet, it is Tybalt's hatred of Romeo that is the cause of all the
death." To support this, you would need to track the events that occur
from Act III, scene i (the scene in which the first deaths occur), and show how it is
Tybalt's hatred that is to blame for the death of Mercutio, his own death, and the
subsequent deaths of Romeo and Juliet.

On a more general
level the hatred could be analyzed through the actions of the Prince.  A thesis
statement here could be:  "By not punishing more severely the initial acts
of hatred in the play Romeo and Juliet, The Prince creates the
environment that permits hatred to flourish and lead to death." In this
case, you would want to examine the Prince's decrees after each skirmish in the play,
and especially analyze his concluding speech in which he states that "all are punished"
at the end of the play.

Good luck with your
essay!