A godly heart, concerned with the glory of our dear Lord, growing in love for God and neighbor, personal holiness, the unity and peace of the Church catholic and of his own congregation, and such unquestionably top priority Kingdom issues, might wonder along these lines: "Is it really very significant if we hold to creation in six real days of ordinary length or not? Isn't the simple truth that God created the world what really counts? Don't the important, timeless spiritual truths abide in Scripture, regardless of the nuts and bolts of how God created, be it in six days or six ages?"
Consider these three passages:
1. Luke 3:36b, 37 -- "...Noah, the son of Lamech, the son of Methuselah, the son of Enoch, the son of Jared, the son of Mahalalel, the son of Cainan, the son of Enos, the son of Seth, the son of Adam, the son of God."
2. 1 Chronicles 1:1-4a -- "...Adam, Seth, Enosh, Cainan, Mahalalel, Jared, Enoch, Methuselah, Lamech, Noah..."
3. Genesis 5:1-29, not quoted due to its length. In this passage, the exact same ten patriarchs listed in Luke 2 and 1 Chronicles 1 are listed in the exact same order, but there is much more detail. It is the [TOLEDOTH], the history of, the generations of, the genealogy of Adam.
Genesis 5 gives the exact number of years of Adam's life (930) from his creation to his physical death, and the exact length of the lives of the other nine patriarchs, his descendants. It gives the year of the birth of each man's son with respect to his father's life, and the exact number of years each man lived following his son's birth.
We are hard put to find anything in the midst of all this arithmetic that might be called metaphorical or poetic; if anything, we might be tempted to think of such a text as "dry, dusty, technical"; we might wonder why the Holy Spirit led Moses to include it in the book of beginnings.
Infinite wisdom no doubt had manifold, wondrous reasons for including it, and that leads to the burden of what is to be brought out in this essay. Here are a few more pertinent passages:
Psalm 12:6 -- "The words of the LORD are pure words, Like silver tried in a furnace of earth, purified seven times."
Matthew 5:18 -- " For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled".
John 10:35 -- "If He called them gods, to whom the word of God came (and the Scripture cannot be broken)..."
Romans 15:4 -- "For whatever things were written before were written for our learning, that we through the patience and comfort of the Scriptures might have hope."
2 Timothy 3:16,17 -- "All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work."
When we recognize that the holy Bible is the well structured, cohesive "product" of the infinitely wise and holy mind of God...when we recognize the claims to its rock solid trustworthiness that God has included in His word...when we recognize that Jesus and the apostles designated the entire Old Testament with terms like "the law" "the word of God", and "Scripture", thereby including Genesis and the other four books of Moses...when we consider Paul's (and Peter's, cf. 1 Peter 1:16-21) apostolic exhortations to trust in the Word and depend on its usefulness...and when we think again of the first three passages cited...
How can we possibly hold to anything but that God created in six days of ordinary length???
Genesis 5, while it is impressing on us how death came into and abided upon the human race ("he lived X years...and HE DIED"), strenuously labors to anchor the ten patriarchs' lives to history. God the Holy Spirit through His servant Moses painstakingly provides the details of the length of each man's life, the year of each son's birth, the year of each father's death. This passage was written by inspired Moses, c. 1400 B.C.
Through another Holy Spirit inspired human author, First Chronicles 1 was written at the end of the Babylonian captivity, c. 500 B.C. He repeats the same list in the same order, without the life span details.
Luke the beloved physician, companion of the apostle Paul, wrote his Gospel under the same blessed Spirit's inspiring power in the first century A.D., and confirms (again without the life span details) what Moses gave us under inspiration, and what the Chronicler previously confirmed for us under inspiration: same ten men, same order of descent.
Now, since each of the three passages gives us the identical list of primeval fathers of the human race in the same order (ascending in Luke), are we not most solemnly bound as believers to hold dearly to it as utterly accurate? Otherwise, it would seem that we are driven to conclude that there has been one gigantic Divine mistake, repeated throughout the 1,500 years or so of the writing and ensuing years of transmission of Scripture from generation to generation, and that the Bible is therefore not very reliable at all. Jesus didn't look at "the law" that way!
If words mean anything, must we not hold instead that the Bible gives us solid truth about the earliest history of our race...a real genealogical list, going from Adam to Noah without any "gaps"? Are we not required to believe that God gave us the number of real years that passed from the day of Adam's creation until "in the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened"? (Genesis 7:11)
Is the holy Bible the inspired, inerrant, infallible, and fully authoritative word of God, the most precious and revered document we possess? YES. And these considerations show that it is impossible to hold a view of Scripture that acknowledges any integrity in it at all AND simultaneously hold to a view of Genesis chapter 1 which denies that its six days are ordinary days, "24 hour" days!
The term twenty four hour is in quotes above, only because unlike God's ordained divisions of time based on celestial time keepers (Genesis 1:14-16), and the week, Divinely ordained but without a celestial time keeper (Genesis 2:1-3), hours are man made divisions of time.
Further reading on this topic: Six Days or Six Ages?