Yes they believe what they preach. They have congregations of people who must also believe most of what they preach, or else they wouldn't have any influence to worry about.
There is a there is a certain amount of smarmy self-righteousness that must be present in a person to even desire to be a pastor, preacher, reverend, priest, rabbi, or any other person whose job it is to tell other people how they should live. I immediately count the fact that someone is a religious leader against them in terms of their character and worth.
From the pope down to the smallest of small town church pastors, they've all found a way to back their ingrained desire to boss people about with a falsified legitimacy provided by an arbitrary authority that they are free to interpret as they wish. Some people get a perverse pleasure from pointing the finger and saying "that one is doing wrong because I say he is" and having the flock agree with him because he's "studied the bible" or "gone to seminary".
These people are not moral authorities by virtue of their own good judgment and wisdom, but by their ability to parrot ideas with a strong and convincing voice. Sometimes they slip in a bit of their own often twisted and immoral opinion in the same voice, so that their followers can't tell the difference. It's despicable when they do that, but I believe that all religious leaders have an element of the despicable about them, like they took the easy path to authority when they may not have had any right to it.
