Light travels at a constant rate. The milky way is over 100,000 lightyears across. To see accross our own galaxy, the universe would have to be at least 100,000 years old. To see Andromeda, the nearest galaxy, the universe would have to be at least 2.5 million years old. There are much further objects in the sky, which we can detect the age of through their red-shift, but I think you get the general idea.
Anyone who says that the universe is 6.5k years old would have to propose the absurd notion that God put all that light in place right there just to trick us, which is an absurd special pleading that can't be taken seriously, and anyone who proposes it as a serious option, likewise, cannot be taken seriously. I don't care if it's your beliefs. Your beliefs are not something precious that is protected from critical review.