Someone shows you a headline: a fossil has been dated to millions of years, so the Bible is wrong. This guide prepares you for that conversation by teaching the dating methods in order, one idea at a time. Then it shows you where Christians who take Scripture seriously disagree about the age of the earth. You can work through it alone in one sitting or with a group over one or two meetings. The source throughout is a Jude 3 Project conversation between Lisa Fields and biochemist Dr. Fazale Rana of Reasons to Believe.
The answer this guide builds toward has two parts. Carbon dating measures how long ago a once-living thing died, so it is the wrong tool for dating the earth. The deeper question underneath the headline is how to read the days of Genesis 1, and on that question faithful Christians hold more than one view. What Scripture plainly requires on every view is that God is the Creator.
First, learn what kind of clock this is
Most arguments about carbon dating go wrong before they start, because nobody stops to say what the tool does. Rana starts with atoms. He explains that “there’s certain versions of atoms in nature. These are called isotopes that are unstable, and they will decay over time to produce other types of atoms.”
Carbon is his example. He describes three kinds in nature: carbon 12, carbon 13 and carbon 14. Carbon 14 is the unstable one, and it decays into nitrogen 14. The key point is that this decay happens, in his words, in a “mathematically describable predictable manner.” A predictable process is a clock. If you know how fast something changes, and you can measure how much change has happened, you can work out how much time has passed.
One picture helps here. Think of an hourglass. If sand always falls at the same rate, the amount in the bottom tells you how long it has been running. Keep two limits of the picture in mind. Nobody stood beside the earth watching the sand fall, so every reading is an inference from present measurements. And the hourglass only works if the rate stayed the same the whole time. That second limit will matter later, so hold onto it and set the hourglass aside.
Try this before moving on
Without looking back, explain in two or three sentences what an isotope is and why a predictable decay rate makes it useful for dating. If you are in a group, have each person say it to a partner. A good explanation uses plain words and leaves out anything about the Bible. You are learning the tool first.
Second, see what carbon 14 can and cannot date
Rana states the scope of carbon dating in one sentence: “carbon 14 is great for something that was once alive.” Then he describes the method: “And so by measuring how much Carbon 14 was in that sample, you’re actually able to determine how old that sample is, knowing that decay rate.”
Notice the two limits built into that description. The sample has to come from something that lived, and the method depends on knowing one isotope’s decay rate. A rock that was never alive is outside its reach. So is the planet as a whole. Carbon dating answers a narrow question: how long ago did this organism die?
Carbon dating also has a practical upper limit on how far back it can reach. The conversation does not give a figure for that range, so treat it as a research task. Look it up in a reliable science reference and write down what you find, along with where you found it. This habit matters as much as the answer. In a real conversation you want to say only what you have actually checked.
Third, find where the big numbers come from
When Fields asked how dating methods seem to put Christians at odds with the creation story, Rana did not point to carbon 14 by itself. He pointed to radiometric dating as a whole family of techniques: “what these techniques indicate is that the Earth is about four and a half billion years old.” He also reports that, by these methods, life has been present on earth for 3.8 billion years and modern humans for roughly a hundred thousand years.
The conversation does not walk through which isotopes or measurements produce each of those figures. Those numbers are Rana’s summary of what the methods indicate. Here is the distinction to carry into any conversation. The billions-of-years figure is attributed to radiometric dating as a group. It is not a carbon dating result.
The mistake to catch
The most common error runs in two directions. One person says carbon dating proved the earth is billions of years old. Another tries to defend a young earth by attacking carbon dating. Both have aimed at the same wrong target. When you hear either claim, you can correct the premise kindly before discussing the conclusion. That one move often lowers the temperature, because you are no longer arguing about something neither of you meant.
Group note: Pause here and check understanding before going on. Ask someone to explain the difference between carbon dating and radiometric dating in general. If the group cannot yet state it clearly, the rest of the guide will feel like a debate about nothing. Spend the extra five minutes.
Fourth, understand the real young-earth question
Now return to the hourglass and its second limit. The clock only works if the rate stayed constant.
Rana is not a young-earth creationist, but he speaks about that position with respect. He says, “I very much respect the methodology of Young Earth creationism because they’re starting with scripture.” Their reasoning, as he describes it, runs like this. If you are convinced that Genesis 1 teaches a young earth, and the measurements seem to say otherwise, you are pushed to ask whether the data are reliable or whether some assumption behind them fails.
He names the Institute for Creation Research as the group that has done, in his opinion, the most and best work on this question. His summary of their study is precise. He says they “basically argued that at face value, it really does look like from radiometric dating techniques that the earth really is several billions of years old.” They do not claim the readings are fake. They question one assumption, which Rana states this way: “the assumption going into this is that the decay rate for radiometric decay is constant.” Their proposal, as he describes it, is that decay may have sped up during the creation week, at the fall, or at the flood. If it did, a young earth could hold samples that look old.
Rana’s response is short: “old Earth creationists generally don’t find them compelling.” The conversation does not lay out the physical reasons. So be honest about where things stand. The two sides agree about what the instruments read. They disagree about whether the rate held steady across all of history. Settling that takes evidence about the physics of decay, not suspicion about scientists or about believers.
Fifth, read the text for yourself
Suppose the radiometric ages are right. The headline still needs one more step: that Genesis 1 requires a young earth. So the question moves from the lab to the page. Read Genesis 1:1-2:3 aloud before going further. Genesis 1 is a carefully patterned account with numbered days and a repeated refrain. Its first line sets its main claim. Genesis 1:1 reads, “In the beginning God created the heaven and the earth.”
Rana argues that the Hebrew word translated “day” can mean the hours of daylight, a 24-hour period, or a longer span, much as the English word can. He insists that reading “day” as a long period is still a literal reading. He puts it this way: “Well, I would actually argue we are reading it literally.” He adds, “by reading it literally, that means we’re paying attention to the original language.” He is also candid about his limits: “I’m not a biblical scholar, I’m a biochemist.” He credits Walt Kaiser for some of his reasoning.
Here are the observations Rana offers. Work through each with the text open.
- Day one names the day. Genesis 1:5 reads, “And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.” Following Kaiser, Rana reasons that if the ordinary day is being established here, the creation day may be something longer.
- The seventh day has no closing refrain. Genesis 2:2 reads, “And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.” Rana notes that evening and morning are not mentioned and takes that to suggest the seventh day continues.
- Genesis 2 expands the sixth day. Genesis 2:8 reads, “And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed.” Rana argues that the garden growing, Adam working it and naming the animals, and then the making of the woman could not all fit into 24 hours.
- Moses and time. Psalm 90:4 reads, “For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night.” The psalm’s heading credits it to Moses, whom Rana also regards as the author of Genesis 1. He treats this as a clue to how Moses thought about days.
Handle that last point with care. Psalm 90 contrasts human frailty with God’s eternity. Second Peter 3:8 makes a similar statement: “But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day.” That passage answers why the Lord’s promised coming has not yet arrived. Neither verse defines the days of Genesis 1. Both show that God does not experience time as we do. That makes a long-day reading possible. It does not prove it.
Now state the strongest case on the other side. Genesis 1 numbers its days and closes the first six with evening and morning. Many careful readers take that pattern as ordinary days. Young-earth creationists build their view on exactly that kind of attention to the chapter, which is why Rana says they start with Scripture.
Sixth, map where believers land
Rana describes three main views among evangelicals. Young-earth creationism holds that the Bible teaches an earth roughly six to ten thousand years old. Old-earth creationism holds that Scripture allows or even indicates an ancient earth, while God acts directly in creation. Evolutionary creation holds that the earth is old and that God used evolution to create. Rana describes that third view as reading Genesis 1 as theological truth rather than historical description. He has held two of these views himself, and he says “every position has strengths and weaknesses. No position is perfect, but at least there’s a landing point.”
What do they share? Rana names the message of Genesis 1 that does not depend on the length of the days: “God is the creator. Everything around us is the product of God’s handiwork. Human beings are made in God’s image.” That is the firm ground. How long creation took and how God carried it out remain questions faithful Christians answer differently.
Practice: rehearse the conversation
This exercise has three rounds. Do it with a partner, or alone by writing your answers out.
- Correct the premise. Your partner says carbon dating proves the earth is billions of years old. In under a minute, explain what carbon dating measures and where the big numbers actually come from. Do not mention Genesis yet.
- State the other view as its holder would. Pick the view on the age of the earth you find least convincing. Explain its best argument so well that someone who holds it would say you got it right. For a young earth, use the decay-rate question and the evening-and-morning pattern. For an old earth, use the text observations above.
- Name the common ground. Close by saying, in your own words, what all three views affirm about God as Creator.
Lisa Fields described the goal as “trying to be honest about science and trying to be honest about scripture at the same time.” Each round tests one half of that. If you are leading a group, let people swap roles. Watch for anyone who mocks a position instead of stating it. Gently ask them to try again.
Questions to work through
- Before this guide, what did you assume carbon dating could date? What specific idea changed your picture?
- The young-earth case as Rana describes it accepts the readings and questions an assumption. Why does that make a different conversation than calling the science fake?
- Of Rana’s text observations, which seems strongest to you, and which seems weakest? What in the passage itself leads you there?
- What would count as good evidence about whether decay rates were ever different? Who would you trust to evaluate it, and why?
- Rana says “science should never be a reason why anybody walks away from their faith.” What happens when someone is taught that the gospel stands or falls with one view of the earth’s age?
- Rana says “We’ve gotta learn how to discuss our disagreements in a way that promotes unity in the body.” What would that look like in your own church or friend group on this topic?
Carry this into the next headline
The next time a dating claim appears in your feed, ask three questions in order. What tool produced this number, and is it suited to this kind of sample? What assumptions does the result rest on? Does the claim conflict with Scripture itself, or with one reading of Genesis 1? Fields put it simply: “I think it’s important for us to think critically through these things.” Working through those three questions is what she means.