I will first deal with the allegory vs. literal, and then the young earth/old earth controversy.
I do not believe that genesis is an allegory for these reasons:
The context as it is used within the new testament shows that adam was one man, not mankind:
Romans 5:12 Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all men, because all sinned—
Also, in exodus 20:11 For in six days the LORD made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.
The hebrew word used in exodus 20:11 and in the creation narrative for "day" is the same word, (hebrew: "yom", yod, vav, mem) and refers to a 24 hour period. If you were to say that it was "periods" or some other length of time then a 24 hour period, you would not use "yom".
It really comes down to faith. Do you believe what the bible says God did, he actually did. The only reason an allegory is necessary, is to try to reconcile the bible with what the evolutionists say about earth, and want to compromise. Infact, that is what all departure from the word of God intends to do, comprmise or ignore what the bible says to justify a different belief than what the bible teaches.
This brings us to young earth/old earth.
I admit, I do not have enough information gathered to offer a comprehensive opinion, but I do believe that the geneology's that the bible states are correct from faith.
Evidence does strongly support a flood about 4000 years ago. This massive amount of water could cause the terrain features that we see today by erosion that at today's flow of water/wheathering would take millions of years to form. You see, if you have all that water from the flood, it is going to change the earth's surface. It is like a like water spigot dripping on a rock. It is going to wear it away, but very slowly. you see a small depression, and calculate how long that water was running by the current flow at that time. What people may not know, that was that they water was running full blast for a year before that. What would have taken the drip 20 years to do could have been done in 1 year with the water full blast.
In short, science cannot prove or disprove a young/old earth age due to the fact that you cannot get correct data without knowing the wheather conditions through all of earth's life span.
In my humble opinion, the earth is probably around 6000 years old.
I base this off of my faith in the Bible and nothing else.
The evidence that the bible is true can be found in the prophesies written down by men who claimed inspiration by God and that came true. Scientifically, it is a reasonable belief, but science purely will never have enough data to raise young earth/old earth theories to a law.
