If you tell a child that the tooth fairy will come to get their lost tooth, they will believe you.

If you tell them that Saint Nicholas will come in December,

they will believe you.

If you tell them that there is treasure at the end of the rainbow, they will believe you.

If you tell them that they are stupid and incapable of anything, they will believe you.

So tell them and repeat every day that they are smart, loved, brave and capable and they will believe you.