Each one of us is distinct, and a true recipient of His glory, but we only light up our own areas influence,  whereas together our lights shine much brighter.  Using the illustration that Christ used to describe us as the "City on a Hill", paints a clear and meaningful picture of the need for unity.   In the ancient world a city without electricity is only lit up by the abundance of individual lamps burning collectively. No single lamp will illuminate much. But together, with Christ's light in each of us, we then will become light bearers in a sin darkened world and can then become that "City on a hill" leading others to Christ and out of the darkness.