Your Church no doubt has a Local Area Network (LAN). This comes with setting up an Internet connection. The portion of that system that comes from the Modem to your computers is the LAN. It can be wired (using Ethernet) or unwired (using WiFi). It is the last leg of the technology that you use to connect. If you have exposed your WiFi to the congregation, then they are all using your LAN.

Given the public nature of a WiFi connection, you should monitor the traffic. You don’t want a drive-by hacker to use your Internet connection to send SPAM (or something worse)! If you suspect a problem, you can always block the WiFi connection while you sort things out. Your Modem should have a administration access (inspect the device for tips on how to access it.) You can log in and see a lot of details about traffic and configuration settings and versions etc. Don’t change any configuration setting unless you’re sure it needs to be changed. Do look for ways to monitor the traffic. You can restrict it in many ways. The most restrictive is to only allow certain devices to use the network. The least restrictive is to allow all devices to use the network. You can block devices that cause a problem. You want to monitor usage to identify any devices that are abusing the network and block them.