What do you mean :S
The divergence theorem just states:
[tex]\int_{\mathcal{V}}(\mathbf\nabla\cdot\mathbf{v})d{\tau} = \oint_{\mathcal{S}} \mathbf{v}\cdot d{\mathbf{a}}[/tex]
This can be applied in electrostatics by:
[tex]\int_{\mathcal{V}} (\mathbf\nabla\cdot\mathbf{E})d{\tau} = \oint_{\mathcal{S}} \mathbf{E}\cdot d{\mathbf{a}} = \frac{1}{{\epsilon}_{0}}\int_{\mathcal{V}} {\rho} d\tau = \frac{1}{{\epsilon}_{0}} Q_{enc}[/tex]