In this paper, we provide a new theory and mechanism to explain how the ground state chemical reactivity for a molecular system can be modified by coupling to the cavity with electronic excitation frequency. Our theory is based on the recently developed Polarized Fock States representation, which are shifted cavity Fock states associated to each specific electronic state. These PFSs are non-orthogonal to each other but provide a compact description of the photonic Hilbert space. Using the recently developed Polarized Fock States representation, we demonstrate that the change of the ground-state potential is achieved due to the scaling of diabatic electronic couplings with the overlap of the polarized Fock states. As the light-matter coupling increases, the diabatic electronic coupling is effectively reduced, resulting in a ground polaritonic potential energy surface that resembles the diabatic potential (associated with the dipole operator's eigenstate).