You hear a siren in the distance and the sound is feint. But as it draws near it gets louder and louder. Then you see the glint of the read beacon on top reflecting off of the sides of the road. You see that beacon (flashing light) and it is a beacon of Hope coming down the road to help you. And when it arrives everything is going to be alright.
I liken this to missionary work in a very simple way. I am dressed in BLACK AND WHITE. I walk down roads.. I am somebodies beacon of HOPE. They see that someone is coming to help them in a spiritual sense. They see my badge over my heart and they know (hopefully) that I am there to bring Peace unto them.