If you walk outside at the brightest point of the day when the sun is completely unobstructed and turn on a flashlight, will that flashlight produce light? Sure it will. Will that light help you to see any better than you already do? That's doubtful since it is already bright outside. The light of the sun will more than likely prevent you from seeing the light that is being produced by the flashlight.
Now wait until its dark outside, a night where the cloud are blocking the moon so very little light is being produced from the sky, go back outside and turn on the exact same flashlight. Will that same light help you to see better than you already do? Yes! Why, because you have now turned the light on in a dark place. There are no other light sources competing for the spotlight (that will preach all by itself, but I won't go there in this post)Matthew 5:16 tells us to let our lights shine before others that they may see our good deeds and glorify our Father in heaven.
If we are only around places that are already filled with light (places where other Christians are gathered together), will our light still shine? Yes, but like the flashlight, it won't help anyone to see our Father any better, because its already daylight in those places. Instead, we should step into dark places, so that our light can be seen and draw people to the source of our light... Jesus Christ. Have you ever watched insects buzz around a light at night? They are drawn to the light. During the day that same light can remain on, but there won't be any bugs around it. Why? Because the sun is out so there is light everywhere. The single bulb gets losts in the sea of light being produced by the sun. The bulb no longer stands out!
To truly have an impact on our dark world, we (those of us that carry the light of the Lord on the inside of us) must begin to go into the dark places so that those that do not know Him, can become drawn to His light! You are the representation of heaven on the earth. If you aren't going into the dark places to allow your light to shine, those places will remain forever dark with no guidance into the light of life.