Adam and Eve had already seen each other with no clothes on, and because they had the whole universe to themselves and a lot of spare time, they decided to play 'mummies and daddies' and made a brand new baby. With all the animals God had made, they probably watched what the dogs and monkeys were doing and decided to give it a try too.

Naughty things like sex are not really supposed to happen until you get married, but in those days there was nowhere to go to church and nobody to invite to the wedding, so they were making the rules up as they went along. God was watching everything they did, and you'd think that they would be too shy to take off their clothes again, but maybe they hid under a bush or something.

Pretty soon Eve had a baby, and God's everlasting punishment made it very messy and very, very painful. Eve said a lot of rude words while it was happening, including one word which accused Adam's mother and father of being unmarried. Adam didn't actually have a mother and father, but he still knew it was a naughty word - he didn't need a bite from an apple to tell him that. No, actually, he probably did.

Adam helped as much as he could, but he wished that God had at least explained how to deal with all the yukky stuff. But God was somewhere else, still sulking about that business with the fruit and the talking snake.

The first baby was a boy, and they called him Cain. They had to wrap him up in leaves because as far as they knew they weren't allowed to kill any more animals to get their skins, and weaving cloth wasn't something they'd been taught to do.

With nothing much to do except make babies, it wasn't long before Eve was pregnant again. Although this time they were hoping for a girl, it was another boy, whose name was Abel.

When Abel grew up he became a shepherd. He probably worked out how to make wool into clothes, otherwise it would be pretty pointless keeping sheep, because nobody was allowed to eat them. On the other hand, he might have used the sheep's milk to make feta cheese, which is very tasty with fresh bread and tomatoes.

Cain took after his Dad and planted crops in the fields. If there was any demand for bread, or salad vegetables, Cain was the expert at producing all the ingredients, so a choice of sandwiches was never going to be a problem for the world's first family.

Of course the two boys were a lot older now, and after all this time God had cheered up a little, and came down to see what was going on with the world. The kids organised a little harvest festival, with Abel showing off his cheese and wool products, while Cain was especially proud of his carrots, onions and baby sweetcorn.

God was particularly partial to Abel's delicious cheese selection and awarded the clever shepherd a rosette which said 'First in Show'. However he turned up his nose at Cain's offerings and muttered something about 'filthy rabbit food'. This really upset Cain, who had tried his hardest, and this was in the days before TV gardening shows and seed catalogues, so he was doing his best with what he had available. God told Cain to stop being so miserable and to get back to work and behave himself.

Needless to say, Cain wasn't very happy about slaving away in the fields all day for nothing, while Abel sat around on a hill, surrounded by sheep and knitting wooly socks. His jealousy got the better of him and he tricked Abel into going to one of his fields. "Let's go out to the field," he said, which just showed that Abel was easily fooled.

Once they were there, Cain went totally crazy and battered Abel senseless with a barrage of root vegetables and stale bagels, before finishing him off completely with a solid smack to the head using his biggest and best (but non-prize-winning) turnip. Abel was dead, and that put the population of the Earth back down to three again.

Unfortunately for Cain, God was still on the scene, and in fact was looking for Abel to ask him if he'd considered using his cheese as a pizza topping. So when he found Cain with a blood-stained turnip in his hands, he suspected the worst.

"Where's Abel?" God asked him.

Cain said he didn't know, and that maybe he was doing some sheep shearing in the next field. But God knew better, because God knows everything, so of course he didn't really have to ask where Abel was at all. Isn't that just like your parents, when they know you've been naughty but they pretend not to know so that you'll own up?

Cain hadn't owned up, so God gave him the greatest punishment he could think of for a murderer. No, not 30 years in prison, this was much worse. God told Cain to go away and wander around a bit.

Cain realised he'd got off lightly, but was still worried that people would hate him for being a murderer and would try to kill him. God thought he had a point there, so he put his mark on him so that it wouldn't happen. The mark was probably some kind of tattoo, or it might even have been an everlasting T-shirt which said, "Don't kill, by order of God." We will probably never know.

What we do know is that the story gets a bit strange from this point, because despite being told by God to wander the Earth, Cain got married, had a son, built a city, and settled down for the rest of his life. So he pretty much got away with murder and had an easy time of it. Plus, he was the only person in the world who could go out late at night and not be mugged or killed, because God wanted him kept alive, so really he was much better off than all the other people alive at that time.

Cain's wife was a bit of a mystery too. After Cain killed Abel, that just left himself, and his parents, Adam and Eve. But the Bible says that he found a wife. Who knows where she came from? Maybe God did some more Creation in his spare time, and there were people all over the place, but you'd think that the Bible would mention it. Trust God to keep us guessing! He's like that, always doing the unexpected and unexplained.

Back in the land of Nod, which really is the name of the place, I promise you, Cain was building a city, which was called Enoch because that was the name of his son. It must have been tough work with just the three of them living there, doing all the bricklaying and the road building, while at the same time growing food and wondering who exactly the parents of Cain's wife were, and who was going to live in this huge city. I suppose it was like an enormous housing project - they had to build it and then find people to move into it.

Pretty soon Enoch was married too, which meant that God really had to be making more women as a hobby, otherwise they would all be related and people would be marrying their own brothers and sisters. However, things were different back then so maybe marrying your own sister was okay. You were even allowed to have more than one wife without God telling you it was a sin, and a man called Lamech did just that. There were soon kids everywhere, living in tents, playing musical instruments, and generally having a great time.

However, Lamech was just like his Cain, and ended up killing someone, so they were probably in desparate need of some kind of city police force and judicial system, to try to stop this kind of thing happening again.

Meanwhile, back in Eden, Eve had another baby, but still it wasn't the daughter she'd hoped for, so if you were wondering if Cain had married his sister, the answer is no. Besides, by this time Adam and Eve must have been hundreds of years old, what with all the descendants of Cain and Enoch being born here there and everywhere. In those days you didn't need wrinkle cream or retirement homes, so old folks could have babies just as easily as their grandchildren did.

This is how the world started to fill up with people, but like a good mystery we don't know what happened in some parts of the story because God forgot to write it in the Bible. So we have to guess about the bits where men find wives, because so far nobody we know has actually had a baby girl.

Do you like the mysterious parts of the Bible? Mysteries are lots of fun, and the Bible is so full of them it's hard to tell if something is real or make believe. Can you tell the difference yet?