"How can I advertise my listing to people in my city?"
There are several places you might post the announcement. To start off, give it to your church's pastor and explain your situation. He would then know where to refer others with a similar need. Next, give it to other churches in the area. Many of them have an announcement board. If there are colleges in your area, ask for their permission to post it on any billboards they have. Other locations, such as grocery stores, are swarming with both Christians and non-Christians. They have announcement boards you can use, but who knows? Perhaps an activist will come on and pretend to be a Christian. They are in your city, so you might be the one getting calls from them.