The are as likely or more likely to believe their creed than their parishoners. There are cases and times in history when those on the top of a religious movement were cynical and did not themselves believe. But I do not think those cases are the norm. I think the pope, for example, is probably not a secret athiest (though there may have been a few like that over the centuries).

A prehistoric shaman huddled with his tribe in a forest is just as terrified and awestruck by an electrical storm as anyone in his tribe. Just because the tribe looks to him for explanation and mediation, does not make him any less affected nor any less needful of faith.