Dinosaur fossils were placed in the earth by Satan to deceive mankind into disbelieving Genesis
Actually, as shown by the Mount Saint Helens eruption and also the Washington State Scablands, large geological formations such as the Grand Canyon can form rapidly under the intense hydraulic pressure of floodwaters. If you think about it, isn't it a bit incredulous to believe that a canyon a mile in diameter was carved by that slender little blue strand of a river at the bottom? If this wasn't about creation-evolution, wouldn't the burden of proof be on those who argued that major flooding didn't erode it?
If the Grand Canyon is, say, forty million years old and Ice Ages occur, say, every forty thousand years, then the Grand Canyon must have been covered with ice over a thousand times in its history. Odd that the Colorado River can leave its mark, but being covered by an ice pack a mile thick a thousand times -- for centuries at a time -- does not.
Couple of questions if you have time. Since we can easily see that there are creatures "beneath" us that cannot possibly ever fathom many things we understand, we can see that there could be a being above us, understanding things we can't understand. That's God. Extend it: He's omnipotent (can do anything). He can create something out of nothing (at least that is how it would appear to us). So say He creates a Universe. How "old" does it look the moment He creates it? What does such a question even mean? I think if you look into it, you will find that there exists no scientific concept for a physical object that has no age! One more thought: if we discard our conditioning to believe that "scientific" methods have "proven" that things are "really old" (it's a belief, and I will challenge you here to prove that you are a scientist who understands any scientific dating method beyond carbon 14) we might think of a young Earth as more a test of our faith (in this age only -- "old Earth as science" is fairly new) than a cruel joke by God.