There are two type of lost people (or I would say responses from lost people) in the world, the moths and the cockroaches. In the darkness, it's impossible to tell them apart, so the best way to discover the difference is to turn the light on. The moths will be drawn to the light, and the cockroaches will fell. Jesus told us that we are a light that should not be hidden even behind stained-glass window (Matt. 5:14-16). Most of us don't turn all the lights on in our home during the day. Why? A lamp isn't needed during the daylight. Light is made for the darkness. "You are the light of the world" (Matt. 5:14). We should be brought out into the darkness so that we can shine." p. 179
Our purpose is to be the light, God has to prepare their hearts, we don't control their response.