It is true that many Young Earth Creationist Christians hold to the view that the world, and universe, is just 6000 – 10 000 years old. This, however, is problematic and goes against everything that the various God-given hard sciences tell us about the world.
The confusion stems from the word yom which is translated as day in English. The Biblical narrative, however, does not state the length of the days of creation in which God created the universe, the Earth and all that is in it. The word yom also has multiple meanings, for instance, it could designate a long, unspecified period of time, a literal 24 hour time period, or can be used as a metaphor (as in my granfather’s day), it may still be used in other ways. In fact, a closer look at the Genesis days of creation negates a literal 24-hour interpretation, for instance, Adam naming all the animals is an impossible task for a single day (Genesis 2:20). The Genesis narrative also says God used the Earth to bring forth his creatures: ‘Then God said, “Let the earth bring forth living creatures after their kind: cattle and creeping things and beasts of the earth after their kind”; and it was so.’ – such necessitates a long period of time rather than a mere 24 hours. In Genesis 1:11 we read that the Earth sprouts vegetation – such would also designate a longer period of time. On the seventh day God rests from his work (Genesis 2:2), hence we are still in the seventh day, and obviously since the end of God’s creation and our present time the seventh day cannot be a literal 24-hour time period.
So, I think it is clearly evident that the Biblical narrative does not teach that the Earth is just a few thousand years old. I also believe that those who hold to the young Earth perspective are outdated, as Nick Peters at Deeper Waters comments that: “The vast majority [of Biblical scholars] I know of hold to an old Earth.”
Perhaps one of the leading intellectuals within the Christian community William Lane Craig remarks:
“Many, if not most, of today’s Christian philosophers and scientists have no problem holding that the universe is 12-15 billion years old and that the earth is probably 4.5 billion years old, and they see no tension with the biblical record. So, one does not need to be committed to a certain age of the universe in order to be a Christian.”
With this very brief analysis of this claim I think it is quite evident that the Bible does not teach a young Earth, and that one is not required to hold to the young Earth perspective to be a Christian.