Can cats get diseases from eating out of the same bowl? I have heard about something that is very serious that cats can get deathly ill or can get something serious from eating from the same bowl. And using the same litter box. (?)

please if anyone knows for sure- please post it here.

I'v never ever heard of anything like that, and I've had cats my entire life. They've always shared a litter box and bowls of food and water, and never passed anything onto each other.
It would be a most difficult task have your cats use their specific bowls and litter boxes...and besides, if you're not at home, they're going to do whatever they want anyway.
Obviously, if one of the animals is very ill, you would want to quarentine him/her from the other cats and their litter boxes and bowls...but I've never heard of keeping tem away from those things "just because".
I'd say just to be sure, you should call your vet and ask her/him. Unless someone on here is a vet...??? I'm not sure if anyone is.

Leave it to a Scientologist to want to use smiling as a form of healing.

my cats have shared everything possible in the last two years and they are disease free.
but if you bring a cat with a disease into your home, i am sure that the other cats in your house will have a good chance of getting the disease as well.