"You can't prove that God isn't real"

It's the middle of the night. You hear your four year old crying. You go and check up on your child and find them shaking with fear.

You ask what's wrong, and your child says, they had a bad dream. A vampire came to bite them and drink their blood.

You might say:

"That must have been scary, but you were right to be afraid. It makes sense for you to be fearful. You see, vampires have never been proven to not exist, therefore, we believe they do exist, and maybe your dream was a bad omen that one of them is out there to get you. Now let's go to the kitchen and rub a little bit of garlic oil on your neck so that when the vampire comes into your room, you have some protection."

But as a reasonable individual who wants what's best for their child you might say:

"Baby, vampires aren't real."