Many of us (creationists and evolutionists alike) often demand "proof" - or present "proof" - for our views; that proof, however, simply cannot exist. What we usually present is evidence. What do I mean?
Let's take this out of the Creation realm and put it more secularly. If you were to assert that there's no such thing as a million dollars, and then demand proof that there is, I would have only one option of proof: to take a physical stack of one million dollars, set it before you, and have you count it. Since I don't have one million dollars, I can't do that. What I can do, however, is offer evidence. I can point to the business leaders and celebrities, which are reported to be worth millions, and use them as evidence. I can print out the Profit and Loss statements of some of the multi-million dollar companies out there and present them as evidence. Do these things prove the existence of one million dollars? No, but they provide strong evidence. Unless we have the physical money in front of us, we cannot prove or disprove its existence.
Now let's move this into the Biblical realm. There has long been a debate about the accuracy of the Global Flood, with both sides continuously offering "proof." While I would love to "prove" the Global Flood, I cannot. What I can do is offer evidence. The existence of this particular myth all over the world indicates that a catastrophe of this sort is quite likely to have happened in the earth's past. It takes far more blind faith to believe that people groups in China, Egypt, the Middle East, India, and North and South America all independently made up a story of a Global Flood. What seems far more likely is that an actual Global Flood occurred, and as the re-developing cultures spread throughout the world, they carried their versions of the story with them. Does this prove the event? Not at all, but it is compelling evidence.
Someone who disregards this story may point to the fact that cultures develop around water sources, and would, therefore, have experienced local - but still catastrophic - flooding. This, however, does not disprove the Flood; it merely sugggests an alternative. I may then, to suggest that this alternative is wrong, point to cultures that thrived off of local flooding, but also had a Global Flood story (the Egyptians in the Nile Valley, for example). What does that prove? The only thing it proves is that they had stories. It suggests that they knew the difference between "Global Floods" and "local floods."
The point is that, as Creationists, we need to be aware that most of our "proof" really is just evidence. We also need to be aware that, for evolutionists, most of their proof is also just evidence. Is the Earth billions of years old? There is evidence to suggest that, but there is also reason to believe that old earth evidence is inaccurate. Without going back to the moment of earth's creation (or the beginning of its development), neither side can "prove" anything, we can only interpret the evidence we have.
What I am finding the more I read the Scriptures and the more I look at the external evidence, is that the evidence points to the Bible as the Word of God - inerrant, useful for encouragement, as well as rebuke. I trust the Scriptures, not blindly, but based on evidence. I believe based on its authority.
C.S. Lewis once wrote:
"Do not be scared by the word authority. Believing things on authority only means believing them because you have been told them by someone you think trustworthy. Ninety-nine percent of the things you believe are believed on authority. I believe there is such a place as New York. I have not seen it myself. I could not prove by abstract reasoning that there must be such a place. I believe it because reliable people have told me so" (C.S. Lewis, Mere Christianity, Book II, Chapter 5).
Lewis would have understood the million-dollar example. Lewis, I think, would have understood the Flood example, too. The question, then, is this: do we believe the claims of people who were not there and did not witness the event, but tell us that it never happened? Or do we believe the people who were there, and wrote about the event? Which, I would ask, is the stronger evidence?