Some christians believe the Earth is only 6000 to 12,000 years old. Where does this age originate from?
No, this is not a universal belief. Some do not take the days in Genesis as literal, and some treat Paradise (as described in Genesis) as being a spiritual world rather than being the same 'world' which we measure with carbon dating and other physical measures.
The 6000 years is roughly discerned using clues from stories in the Bible, but there are other measures placing its age closer to 7500 years.
What is generally used is the following:
It's a lot of work to do, really.
Variations in measures can be explained by differing interpretations of 'day' in Genesis, whether 'in the xth year of y' means that x years preceeded it or x-1 years, and estimates of times not explicitly mentioned.
The "young earth" figure comes from treating the descriptions of the creation of the earth in Genesis as a literal, continuous, description of earth history. It's fairly simple to do the calculation, adding up the ages of each person described, and concluding how long ago Adam and Eve happened. It was most famously done by Archbishop James Ussher.
Most Christians do not believe that the earth is that age, but a substantial minority (mainly in the US) do. See Wikipedia.
The discussion of the evidences for and against is far too complex to give even a summary here.
I'm a young earth creationist.
No, not all Christians maintain this belief. Christians can identify themselves with two different categories, Young Earth Creationist (YEC) or Old Earth Creationist (OEC).
As a YEC believe that God is more then capable of creating everything in six days and that the earth is less than 10,000 years old. As a YEC my argument originates from the following beliefs.
The flood event
The Bible talks about a huge flood about ~4,500 years ago. IF you look for the evidence of this flood you'll see that there's actually a lot of evidence. Walt Brown has done some great research on this topic. He holds true to scripture and does not deny any verses.
The reason that I mention this flood, is because the flood did some major devastation to this planet when it occurred. In young earth creationist POV we see that the sediment layers, massive fossil deposits and more where created because of this flood. The continental shelves and the oceans were also created because of the flood event.
The only evidence that one has of an earth that's millions of years old is chemical dating. One thing that has recently been learned about chemical dating, is that if things are left in water then that thing's chemical dates will show the thing to be much older then it actually is.
Well, if all fossilized animals that we're finding today were put there due to a large flood, then it would make sense that the chemical dating shows those fossils to be older then what they actually are.
More evidence of young earth is given by our current population numbers. If we're the product of millions of years of evolution then we would see an obvious over population issue. But we don't see that, have you ever driven through Wyoming? We're not overpopulated. The entire human race could fit into the state of Virginia with room.
If you do a backwards calculation of our current population you find a small group of people ~4k to 6k years ago.
I use the word decay very vagly here. The moon is drifting away from our planet. One million years ago and the moon would have been touching the earth. The sun is shrinking because of the constant amount of gases being burned. One million years ago and the sun would have been so hot that no life could have existed on earth. The planet is losing is magnetic field. People chalk this up to some kind of polar shift, which has never been seen or reproduced on any magnetic, ever.
We have NEVER witnessed a single star forming, know of one that has recently formed or even know how it would be possible. Scientists calculate that it would be impossible for debris to crush together to form a planet. They have no idea how this could happen. Granite is the same way, there's no way to create granite, it's impossible to have formed from molten lava.
IMHO, those of weak faith believe in man and those with stronger faith believe God. To answer your question, THIS IS WHY some Christians believe in young earth.
When voting on this comment do not downvote because you disagree, as this is not an arguement as to whether or not I'm right. This is merely an answer to the question "Do I maintain a belief that the earth is young, and why."
I'M NOT DEBATING WHETHER OR NOT THESE ARE FACTS.
Again.. I'm not stating these as facts, I'm stating them as my beliefs as a YEC.
As mentioned elsewhere, the Young Earth belief comes from a literal reading of Genesis.
Problems do arise when we try to insert the day-age theory. Assume for a moment that one day is 100 million years. The symbiotic relationships in creation would be separated by hundreds of millions of years.
Additionally, if Adam was created on the sixth day, and the sixth day is 100 million years, if we trace down from his line, we would still be in the sixth day... or, if he was created on the last moment on the sixth day, we would still be early on the 7th day.
Also, why would we ever read 'day' and think 'millions of years'. The only reason would be what we have heard from scientists. However, every person is biased and brings that to bear upon the conclusions they draw. Darwinism is a theory based on assumptions that cannot be proven.
Several pieces of evidence for a young earth are based on the fact that things are wearing out:
The list goes on and on. So, there is a biblical reason to believe in a young earth. Science has failed to prove evolution or deal with the problems mentioned here as well as numerous others.