Some people say the word "day" in Genesis may have been used symbolically and is thus not meant to be taken literally. However, an important point that many fail to consider is that a word can never be symbolic the first time it is used! In fact, a word can only be used symbolically when it has first had a literal meaning. In the New Testament we are told that Jesus is the "door." We know what this means because we know the word "door" means an entrance. Because we understand its literal meaning, it is able to be applied in a symbolic sense to Jesus Christ, so we understand that "He" is literally a door. The word "door" could not be used in this manner unless it first had the literal meaning we understand it to have. Thus, the word "day" cannot be used symbolically the first time it is used in the Book of Genesis, as this is where God not only introduced the word "day" into the narrative, but also defined it as He invented it. Indeed, this is why the author of Genesis has gone to great lengths to carefully define the word "day" the first time it appears. In Genesis 1:4 we read, "And God saw the light, that it was good; and God divided the light from the darkness" called "night." Genesis 1:5 then finishes with: "And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day." This is the same phrase used for each of the other five days and shows there was a clearly established cycle of days and nights (i.e., periods of light and periods of darkness).

A DAY AND THE SUN

But how could there be day and night if the sun wasnt in existence? After all, it is clear from Genesis 1 that the sun was not created until day four. Genesis 1:3 tells us that God created light on the first day, and the phrase "evening and morning" shows there were alternating periods of light and darkness. Therefore, light was in existence, coming from one direction upon a rotating earth, resulting in the day and night cycle. However, we are told exactly where this light came from. The word for "light" in Genesis 1:3 means the substance of light that was created. Then, on day four in Genesis 1:14–19 we are told of the creation of the sun which was to be the source of light from that time onward.