"And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day." Genesis 1:5
God in the Genesis one record tells of the events of the creation of the world. He also tells us how long he took to accomplish it. All of the events of the creation of the world were accomplished in six (6) days. Then on the seventh day God rested. There have been many in the world and now many in the church who question, if not outright deny that this could be true. Let me say at the outset of this article that I am of the belief that if God had chosen to use one one millionth of a second to create the universe he could have done it. For God is ALL POWERFUL! But if he in is his wisdom choose six 24-hour days then that is fine with me. Let's look at the need for some to believe something other than what God has said, and briefly look at some of the evidence that we can know what God says is true.
Why do we not believe that creation could be six days? Well, to put it very bluntly, the most popular and influential scientists believe that the earth shows evidence of billions of years, and so that is how old it must be. There are many who will believe the frail wisdom of man over the infallible knowledge of God, and try to find a way to make the two fit. But to do this without disagreeing with the scientists, requires that we modify, or find room for these ideas in what God has said. There are several ways that man has tried to do this. The Day-Age Theory, the Gap Theory, the Untimed-Undated Theory and others have been put forth as ways to accommodate 4.5 billion years and the biblical six days not so very long ago. The Day-Age Theory says that each of the days in Genesis One is really a vast period of time, during which the gradual changes of living things occurred. The Gap Theory says that between each day of creation was a vast space or gap of time that passed, and so there could have been a small amount of time, or a huge amount of time including 99% of the earth's 4.5 billion year history. Obviously there are other modifications and ideas surrounding this issue of the age of the earth, but that is another article. However one thing needs to be pointed out and remembered, that the only reason not to have the creation days as six-24 hour days relatively recently, is to give time for organic evolution, which, "if" it could occur at all would need vast periods of time!
How can we know for a fact that the days of Genesis One are 24-hour days? First, God defined what the day was, "And the evening and the morning were the first day." That is, a period of light and a period of darkness marked a day. This has not changed since the creation week! Second, when the word day is preceded by a number in the Hebrew, it always meant a 24-hour day. Third, the concept of a week has no meaning if they were not 24-hour days. For unlike all of the other periods of time which have an actual astronomical event to mark its passing, a week is represented only by seven repeating units of light and darkness which is established by God in Genesis One. Fourth, the six 24-hour days of creation are the only ones that have any other proven biblical evidence to back it up. "For in six days the Lord made heaven and earth and all that in them is" Exodus 20:11, 31:17. There are none of the other theories that are repeated and confirmed by inspired text other that this one. Fifth, if we do not take literally the account as given by God in Genesis One, why should we take anything in the first eleven chapters literally? That means if Jesus and the apostles took them literally, they really did not know what they were talking about and so are not a very reliable guide for our souls salvation.