19 Furthermore, hearken unto the Apostle who said, Every man according his work shall receive his reward. He that toiled little, shall receive according to his remissness; and he that made much speed, shall be rewarded according to his speed. And Job also said, Far be it from God to do iniquity; and far be it from Him to do sin. For according to a man's works will He reward him, and a man shall receive according his ways. And also the Apostle said, Star excels star in brightness.
So also is the resurrection of the dead</em>. Therefore know that, even when men shall enter into life, yet reward shall excel reward, and glory shall excel glory, and recompense shall excel recompense. Degree is higher than degree; and light is more goodly than light in aspect. The sun excels the moon, and the moon is greater than the stars that are with her. And observe that the moon and the stars are also under the power of the sun, and their light is swallowed up in the splendour of the sun.
And the sun has power along with the moon and the stars, that he may not abolish the night which has been separated from the day. And when the sun was created, he was called a luminary. And observe that the sun and the moon and the stars are all called luminaries; but luminary excels luminary. The sun obscures the light of the moon, and the moon likewise darkens the light of the stars; and star excels star in its light.
Source: Demonstrations (New Advent)