This diproves creationism (not christianity or any other religion)?

Some creationists will say that, when god created the universe, he created the light from those distant objects ALREADY EN ROUTE to the Earth, thus making their god a liar, and other creationists will say that the speed of light has not remained constant over the eons, thus making their god a trickster. Creationist beliefs ought to be considered heretical, but for some reason, or rather the lack thereof, they are endorsed by many churches.