Several years ago, I was at a lighting seminar as part of continuing education for electrical engineering. As part of the course, the speaker was talking about the efficiency of light fixtures, which is figured by comparing the input energy to the light output. The higher the light output and the lower the energy input, the more efficient the light fixture is considered to be.
The speaker said, “The most ideally efficient light fixture is one that is turned off. You aren’t getting any light out of it, but it is not using any energy.” That drew some laughter from around the room, as you might imagine.
Then he said, “Of course, a light fixture that is never turned on serves no purpose.” His point was that no matter how efficient you might consider a light fixture to be, if you aren’t getting anything out of it, then what is the point of even having it around? That has stuck with me for all these years.
He was speaking from a strictly secular, product-oriented view, but those words really echo something that Jesus said during the sermon on the mount:
No one lights a lamp and puts it under a basket, but rather on a lampstand, and it gives light for all who are in the house. – Matthew 5:15 (HCSB)
This came right after Jesus had said, “You are the light of the world.” He was saying that even though we are God’s light, if we keep that light hidden, then we are not doing any good at all. Much like a modern-day light fixture that is turned off. Yes, it is a light, but the people around it are still in the darkness.
Just like with that light fixture, there is a cost associated with the light, and that cost is your time and energy to actually do something, but the benefits are definitely worth the cost in this case. No spreadsheets or fancy calculations are required to figure that out.
What Jesus says right after the above sentence is just as well known:
In the same way, let your light shine before men, so that they may see your good works and give glory to your Father in heaven. – Matthew 5:16 (HCSB)
He is saying that in the same way that you don’t hide or turn off a light in your house, we should not hide the light that God has put inside of us, but rather we should shine that light in order to glorify God and lead others to Him.
If we don’t use the light that God has given to us to be His lights in the world, then we are serving no purpose at all as Christians in the world. Turn on your light!