I don’t think the issue is “how old the earth is” really - I think the issue is “what is time, exactly?” There is clear science that indicates time is not a constant - and it’s related to the speed of light - which has not been constant over all of time either. There are perceptible, measurable and predictable differences in the world’s official atomic clocks depending on their altitude.
Can you image the difference in the speed of time from earth to say, the next galaxy? It is quite possible that the earth was created in six days as we know them, AND that it’s 16 billion years old - are both correct. Depends on where you are keeping time from.
Then there’s the fact that time and space are actually the same thing ultimately....and we worship a God not confined by time or space. As Einstein said, the idea the there is a difference between the past, present and future remains a stubbornly persistent illusion. (paraphrase)
“....and we worship a God not confined by time or space.”
Bingo!
Human time is not God Time because God is infinite and therefore exists outside of the constraints of human time.
For the Greater Glory Of God
Observation: light does not experience time. When we observe light from “the farthest objects in the universe, peering back in time close to the Big Bang”, that light has experienced travel across that vast distance in zero time (regardless of whether we perceive it as 6,000 or 6,000,000,000 years). I’ve been trying to wrap my head around the “photonic model of the universe”, with slow but interesting results.
Flip-side observation (tangent): light isn’t as fast as we intuitively believe. In the time it takes the light from these letters on your screen to reach your eyeballs, your computer has carried out a dozen or so instructions.
You should read some of John Walton’s books on Genesis. He is a professor at Wheaton. He is coming up with some real mind blowing interpretations that if correct, absolutely destroy the perception that science and Christianity are at odds.
This book concludes much the same thing: http://www.amazon.com/The-Science-God-Convergence-Scientific/dp/1439129584/ref=sr_1_1?ie=UTF8&qid=1412942184&sr=8-1&keywords=Gerald+Schroeder