It's quite common for Christians to accept the idea that Adam was created as fully mature and functional human adult; if you met Adam on day 8 of Creation, you'd meet a fully mature human male, not a newborn.
And yet for some reason we stumble over the idea that a planet, star, or galaxy must be older because it looks that way and go wimpering off into a philosophical corner to devise the Genesis Gap Theory or some other claptrap.
If you are a fellow Creationist, how do you resolve the appearance of an "old" universe? Why can we see galaxies billions of light years away? Why would the universe be created with the appearance of age? Why are so many Christians willing to cave in and concede an old universe?
The answer to the "but outer space looks old" problem is simple, if you believe in God--and by God, I mean the omniscient, omnipotent, omni-benevolent, eternal Creator of the entire thing we call "The Universe". This means He can do anything consistent with His character, not limited by my puny imagination.
God created every thing we can know, including the means by which we know them.
God created not just the physical stuff from nothing, but also the dimensions in which that stuff exists.
Let that soak in for a moment. Ready? Good.
We measure the universe and move through it in three dimensions. We also understand a fourth dimension through which we move in a single direction, yet over which we have no control: time.
Think on that. God created time from nothing. And since He is eternal, existing outside time, He has the complete control of it, including the freedom to start the clock at any point.
I have no problem with the "fact" (and I use that term loosely) that various human means of measuring age of things all result in different numbers. Most of it depends on where--rather when--you started counting. And God didn't have to start at zero.
God created everything fully mature, functional, ready to use. Including time. So I must conclude that the universe appears old and massive because it needs to in order to function properly. Just as Adam appeared fully mature the moment he was created, so were the galaxies. What's the difference if it's 30 years vs. 30,000,000 years? We're talking about an infinite God!
Just like everything else He made, the vast galaxies billions of light years away--and the light by which we observe them--were created ready to meet their purpose.