Let me say it from the very beginning...I believe the Bible says what it means and means what it says, and that therefore, God has spoken in a way that He clearly means for us to understand what He has said and to accept what He said as true.
The Bible does use metaphors on occasion to express a spiritual meaning; "I am the door...." But where it uses such tools of language, it is clearly expressed as a picture being used to illustrate a spiritual truth; that is that those who would desire to come to the Father, must come through the Son.
But there are other times where the Bible is clearly speaking in a manner that is intended to be understood as documentation of actual/historical events. This is why there are so many genealogies. The genealogies put the recorded events into the context of a historical reference chart. These genealogies go all the way back to Adam, while claiming that he was present on the sixth day of space, time and matter, and though there are some slight differences in them, there is no reasonable way to add 10's of thousands of years, let alone millions or billions.
The Bible claims that before Adam's sin, there was no death and suffering in the world. In fact God states that the whole of creation was "very good." The record of Genesis 1-11 tells us that death entered the world through sin, and that the whole of creation was cursed as a result of Adam's sin (see also Romans 1, 8). It tells us there will be a time when all of creation is re-created into a universe that will be able to last forever (Revelation 20-22). In that creation, there will be no more sin or death...no more curse upon the creation.
This is why it is disturbing when christians denigrate the Biblical record of our origins. They claim to accept the spiritual truths which God is communicating as being entirely TRUE, while at the same time rejecting the historical truths God has communicated as being entirely FALSE. In a very real sense, they are calling God the "communicator of the greatest truths who can't be trusted to tell the truth."
Check out Alber Mohler's commentary on this in reference to an article that just came out in Christianity Today.