But there is evidence Santa Claus exists...Easter Bunny also.

I beg to differ.

Many religious people aren't dumb. They misguidedly place their trust in a community that has been around for centuries.

I place my trust in science. A level of trust, that as an atheist and skeptic, I shouldn't have.
I do not have the expertise or resources to verify the claims made by the scientific community.
For the 'softer' sciences such as psychology and social sciences I can tend to succumb to confirmation bias - I will tend towards socialist policies and be very wary of right wing politicians.

Christians (+other religions) aren't that different, they are comfortable with their beliefs and see no reason to challenge them. The fear of loss of community and fear of change means they are happy to accept the explanations of apologetics.

Calling them dumb isn't helpful and won't endear them to critical thinking or help the atheist agenda at all.