God made two great lights — the greater light to govern the day and the lesser light to govern the night. He also made the stars.Genesis 1:16
The great question is never
Why? The answer to the question,
Why did God make the sun and moon and stars? is given in a threefold way here in this passage.
The greater light exists, first, to give light upon the earth, both during the day and at night. We all know that the sun makes the day. The rotation of the earth is what determines the length of the day, and the speed of the earth as it rotates determines the 24-hour duration. Yet that speed is regulated by the moon, which acts as a brake upon the earth. It restricts the speed of the rotation of the earth to the exact time that makes possible the 24-hour-day, which is the length of time best adapted to the needs of humans. Isn't that remarkable? Other planets have entirely different lengths of days. On some of the planets, a day would occupy months, and even years, of our time. Others have much shorter days. But God has designated a 24-hour day for our planet because it precisely fits the needs of humanity.
Second, the great lights exist to measure the process of time
for days and for years, says the Scripture. They are the means by which we measure time. The orbit of earth around the sun determines the length of the year, which, again, is just right for human needs. The orbit of the earth around the sun is determined by two factors: the gravitational pull of the sun and the velocity of the earth. No one knows what determines the velocity of the earth, what strange force hurls us through space at about 1,100 miles per minute. But here we are told that God has ordained the sun and moon to provide measures of the time that mark off the segments of life we call days and years.
Third, these lights are designed to mark significant events; they are
for signs and for seasons. The entire record of human history confirms the truth of this. This is exactly what the sun and moon and stars do. Eclipses are like mileposts in human history, marking off certain dates. We can study events in ancient history because eclipses have been recorded. Many times in the Bible the sun and the moon have served as great signs. We are all familiar with the story of the star of Bethlehem. It announced the birth of the greatest person ever born in the history of our globe. There is also the strange darkening of the sun at the time of the crucifixion, an unexplained darkness that lasted for three hours. There have been other times like this. And through the Bible there runs a refrain, beginning in the early books and running through the New Testament, which says there is coming a day when the greatest event the world will ever know, the return of Jesus Christ to earth, will be heralded by the darkening of the sun and the moon's turning to blood. These bodies are provided for signs and for seasons.
You are the Lord of all creation. I see that you have created the signs and seasons to serve Your great redemptive purpose in Jesus Christ.
Speculation can unceasingly ask how and why questions. How the seasons came to be we will never know while citizens here. But where can we find the why answers?