There seem to be some people who are confused as to why the resurrection of Jesus can make or break the argument for a young earth. On the surface this is not obvious.
Why do Christians care how many days it took to create the earth? I don't. It could have taken God half a second. I could have taken Him 40 trillion years. Why do Christians (myself included) put stock in the fact that Genesis 1 states that it took 6 days?
Because Jesus Christ says that the Law and the Prophets (Genesis included) point to Him. He endorses the Old Testament on several occasions, including a quote of Genesis 2 when discussing marriage and divorce.
Because Jesus Christ rose from the dead, a clear indication that the claims He made about Himself were true, including His endorsements of the Old Testament. Jesus rose from the dead showing His followers that He really was the Son of God.
If Jesus did not rise from the dead we are, as Paul says, to be pitied above all people. The resurrection proves that Jesus Christ has the authority to make the claims that He made. But if He did not rise, then His authority is not real. And that means we do not have to take seriously His endorsements of the Old Testament.
I have had several comments from people who seem to think that there is no evidence for this. I challenge you, look into it. Give it an honest look. Compare the historical evidence for the resurrection of Jesus to the historical evidence for other ancient people and events. The worst thing that can happen is you learn a thing or two about ancient world history.