Good question... well, to me personally this indeed is impossible. Once you start understanding human psychology and all the effects, I find it ridiculous to see people still "believing". But yes, apparently there are still some psychologists out there who should KNOW how the mind works and how easily you can trick it, but still choose to believe. (Fortunately those believers are the minority...)
Are you (somehow) from the field too? (Psychology, that is. Not faith ;-) )
PS: Please feel free to join the group "European Atheists" ;-) See you around? Take care...