In the early 1820s, Augustin Fresnel, a French physicist, invented a new lens that could concentrate light into a relatively narrow and bright beam. In 1823 he installed his creation in the Cordouan lighthouse, which is located on a rocky islet at the mouth of the Gironde estuary off the western coast of France.
In the years preceding Fresnel’s invention, lighthouses used burning coal or oil lamps backed by mirrors to cast light out to sea. Unfortunately, these lamps were too dim to cut through the darkness of heavy storms, and many ships ran aground. Crews were lost as a result.
Now, with Fresnel lenses, lighthouses could send their lifesaving warning many miles out to sea. Soon thousands of lighthouses used the new lenses, and the revolutionary technology eventually was called “the invention that saved a million ships” and lives as well.
In Matthew 5, Jesus calls His followers to be lights in the world and to let those lights shine through good works in such a way that people would praise the Father in heaven. Our lights may be little, as the song goes, but focused by the lens of the Holy Spirit the beams will shine brightly and far, sending good news and a warning throughout the world.