Reasons for the Sun:
1) Separate day from night
2) Mark the passage of time
3) To light the earth
4) To declare the glory of God
1) Separate day from night
2) Mark the passage of time
3) To light the earth
4) To declare the glory of God
And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
The heavens declare the glory of God; and the firmament sheweth his handywork.
Genesis 1:14,15 Psalm19:1