Based on a talk by John Lennox, at the Keswick Convention 2013. He is Professor of Mathematics at the University of Oxford and a lecturer at the Oxford Centre of Christian Apologetics.

For some people, this subject is controversial. We come across a series of 'days' in Genesis 1:3-31. This issue has vexed many people. But the status of the days of Genesis 1 is clearly not the same as the status of the doctrine of Creation, the doctrine of the incarnation, atonement, resurrection and second coming - for one obvious reason. You will find equally godly believers, committed to the authority of scripture, who agree on all of those doctrines, but differ in their views of the days of Genesis 1. That ought to warn us that the matter is more complex than some admit.

Differences on these matters happened centuries before Darwin. They noticed that days are mentioned in the passage before light is created, which caused them to think. Yet, [now] we see evangelicals fighting like children and bringing the gospel into disrepute about things that may not be of first importance.
If I'd been giving the Keswick Lecture in 1633 – it wouldn't have been on the date of creation or the status of the days. It would have been about claims that the earth moves around the Sun, from Galileo, when Scripture says explicitly in Psalm 104:5, that the Earth will never be moved.

Many believers over the centuries believed the Earth would not be moved on the basis of that Scripture. But Galileo, who proposed that the Earth moved around the Sun, did believe in Scripture and wasn't an atheist. The interpretation of these apparently utterly explicit scriptures has changed. So how do we understand Scripture?

The word 'literal' can have different meanings. I'm frequently asked, do I take the Bible literally? I understand what people mean. But nobody takes the Bible literally in its entirety. Jesus said, 'I am the door'. Well, what sort of wood was he made of? The difficulty falls on the understanding of the word literal - it's ambiguous and highly misleading. Jesus IS a real door, into a genuine experience of God. He's literal at that level, but not at the base level.

When a metaphor occurs, the next question to ask is what is it a metaphor for? Just because it's a metaphor doesn't mean it doesn't stand for something real.
In Genesis 1, 'God said' doesn't mean God had a voicebox and lungs. But we can understand that it means that God communicated in some way. It's not meant to mean that God produced a voice. Literature is full of that kind of metaphor. If I say my heart is broken, it doesn't mean I need to go to hospital. All of language is like that. The Bible is full of it.

The word 'literal' is a word to be avoided because it confuses people. Usually it's obvious, such as Jesus and the door - we know what he means.
Metaphors do stand for realities. We now know Earth is stable in its orbit, for example - so the idea that the 'Earth cannot be moved' is based on a reality. 

How do you know Jesus isn't a door? Because we know something about the natural world. We use our knowledge of natural world to interpret things all the time. So, to argue against using science to interpret the word of God isn't very sensible.

There are a number of ways of interpreting the days of Genesis 1. There is the Youth Earth view, that it was created in 6 days. There is the 'day age' view, that the days represent periods of unspecified time. Thirdly, there's a view that the days are in logical, but not chronological order.

There are other views and so many of them. Why do they differ? Before we decide what the text means, we need to look carefully at what it says. So let's try to set aside any of our prejudices – we've all got them – and look at what the text actually says, at the use of the word 'day' in actual text.

Verse 4 and 5 says that God called light day and darkness night. Is that a 24 hour day? No. God called the light day, and the darkness he called night. This draws our attention to the fact that we use the word for daytime, and we also use it for a 24 hour period. So its first use in Genesis is not a 24 hour period. The second use is in verse 5, it would appear, is a 24 hour period.

There are other uses of the word 'day'. When I say 'in my young day in Cambridge', you would never think was that Tuesday or Wednesday. There are several meanings of the word 'day' in the Biblical text.

Notice, that the first verse, 'In the beginning, God created heavens and earth', does not occur on day 1. It's obvious within the literature, that the beginning is not day 1. The tense in Hebrew indicates that the events in the first two verses occur prior to the description of the six days. So, it doesn't matter what you think about those six days, it doesn't tell you anything about the age of the universe at all. All this controversy about the age of the Earth, yet scripture says nothing about it!

Although we could, obviously, claim that Genesis 1 is teaching that the Earth is young, it's not the only way the text can be understood. You don't have to interpret it that way.

Let's think about the idea that the six days are in a single week. Where did we get that idea? How much space is there between those days? I don't think the text tells us. You can understand it in terms of a single week, but you don't have to.

If you agree life has existed for a long period of time, then you have a problem with the entry of sin into the world. I take that problem very seriously. If Genesis is wrong, about the origin of sin and death, then how could we know the New Testament is right in its solution?

Look exactly at what scripture says. Romans 5:12 tells us that sin entered the world through one man – and it's the death of humans that is a result of sin. That's authoritative scripture. Human death, according to Paul, is the result of sin. Animals and fish did not sin, and they die, as part of nature.

In John 11:10-11, Jesus refers both to the light of sun, and spiritual light. The Lord was reading a spiritual lesson from Creation. We are helplessly dependent on a source of energy that's millions of miles outside of our world. If the sun was to go out, all energy and life would die within a few minutes. We are living at the heart of a vast object lesson, we are dependent for our energy and light on a source outside our world.

What about at a moral and spiritual level? This whole thing is a colossal metaphor for something very real. Jesus said, 'I am the light of the world. If you follow me, you won't have to walk in darkness, because you will have the light that leads to life.'

There is a far bigger light than the Sun. You can be dependent on it, and have the light of life. But I fear that some people are more interested in following men than in daily following the light of this world.

This is what Genesis is about. In the beginning, God said... let there be light.