Comment: It is unproductive to call another belief system dumb...

Any type of deist will claim with absolute certainty that a god (or gods) exist(s) while an atheist will claim with absolute certainty that no god exists. As far as being able to prove either point, the footing is equal. Issues of faith are always of this nature. For instance, the existence of ghosts is another example.

Backtracking a little, some atheists may call Christianity dumb. Some Christians may call atheism dumb. Some Christians may call Islam dumb and vice versa. One thing is for certain, none of these people casting stones are making any progress towards peaceful coexistence. Intolerance is never productive.