*cracks knuckles* Time for another one of my famous "You can prove anything with the Bible" shindigs.
It says that God cares enormous amounts for even the sparrow.
Cats eat sparrows
You are what you eat
Therefore, God cares even more for cats.
At the birth of Jesus, Herod (deceived by Satan) (Don't get into a huge theological argument about this) killed all they young 'uns.
Therefore, Satan is against young things
Therefore, God is for young things
Kittens are young cats
So there is plenty of stuff against kitten killing in the Bible. You just have to look for it.