The sun, moon and stars are set in their place for these reasons:
1. To divide the day from the night
2. To be a sign or a signal….like a banner, distinguishing mark, or warning
3. To be able to identify seasons, which are YHWH’s Appointed Feasts times
4. To be able to measure days…. from sunrise to sunset
5. To give light upon the earth
Genesis 1:14-18 ….Then YHWH said, “Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons, and for days and years; and let them be for lights in the firmament of the heavens to give light on the earth”; and it was so. Then YHWH made two great lights: the greater light to rule the day, and the lesser light to rule the night. He made the stars also. YHWH set them in the firmament of the heavens to give light on the earth, and to rule over the day and over the night, and to divide the light from the darkness. And YHWH saw that it was good.