Belonging to the Catholic Church gives your support to an organization that conceals and protects child rapists. Again, not as a few isolated incidents, but as a massive, institution-wide culture, a matter of policy even, that extends throughout the organization and reaches all the way to the top. Belonging to the Catholic Church - giving them money, letting them count you in their rolls, sending your children to their schools - gives this behavior your personal thumbs-up, and actively enables it to continue.