Mat 5:14 You are the light of the world.
The moon shines because its surface mirrors the light from the sun. The perceived brightness of the moon from earth relies on where the moon is in its orbit around the planet.
The words of Jesus “You are the light of the world” are part of His Sermon on the Mount. Jesus is discussing the Beatitudes, how Christians should be like. Earlier He had called them salt, now He calls them light. He is practically saying that believers are called to be salt and light in the world
Jesus is the light of the world (the Sun), in Him, there is no darkness yet here He calls His children the light of the world (the moon). All Christians are light in the Lord (Eph 5:8) and must shine as lights (Php 2:15) as ministers in a special manner. Christ calls Himself the Light of the world (Joh 8:12), and His workers with Him have some of His honor bestowed upon them (joint beneficiaries with Christ) to reflect to the world.
Genuinely, the light is sweet, it brightens the day, it invites, it’s pleasant to the eyes. The world sat in darkness, Christ raised His disciples to shine in it. They so much do so from Him in whom they derive their light. It must be applied here by our Lord to His disciples that they can only shine with His light upon the world, in virtue of His Spirit dwelling in them, and the same mind being in them which was also in Christ Jesus, (Christ like).