A star has its own light source - similar to our sun. It looks small, because it is very far away. The moon, on the other hand, does not have any light source. It merely reflects the light from the sun.

Nonetheless, the moon can brighten the night sky, depending on its phase, much more than the stars can. When the entire surface of the moon that is facing the earth reflects the sun, we get the full moon. This is when the moon is at its brightest, outshining everything in the night sky.

Similarly, when all of my life fully reflect God's love and holiness, my light shines fully. For God's glory.

"You are like light for the whole world. A city built on a hill cannot be hidden. No one lights a lamp and puts it under a bowl; instead he puts it on the lampstand, where it gives light for everyone in the house.

In the same way your light must shine before people, so that they will see the good things you do and praise your Father in heaven."

(Matthew 5.14-16 GNB)

See: Moon phases