Protecting a house of worship is something that requires a comprehensive security plan. Technology (access control, cameras, etc.) may play a role, but is only a very small part of the picture. As Brian stated, it begins with a security risk assessment. This assessment will define and prioritize the specific security risks and threats that the organization faces.
Once the assessment has been done, a security plan needs to be created. This plan will provide the details of how each specific security threat will be managed. In an environment such as this, effective security policies and procedures, training, and security staffing are usually the most important aspects of the plan. Electronic security systems may be a part of the plan, but are never the only thing that should be done, and rarely the first thing that should be done.
With all due respect, most integrators do not have the expertise or experience to conduct a security risk assessment or prepare a comprehensive security plan. I would suggest this client hire a qualified independent security consultant.
There is at least one consultant that I know of (Jim McGuffy) that place an emphasis on serving houses of worship. He operates an informative website with some great info on church security: Church Security Consultant
Most other consultants who have practicing for a while have probably done at least a few churches in their time. Because most religious organizations have little or no money to spend on security, many consultants will often do projects like this for free or for very little charge. I recently did a "pro bono" project for a small daycare center affiliated with a church in the Seattle area.