I remember an old Roman Catholic priest, many years ago, who told me that clergy were brought down by the "Four B's"- Books, Broads, Boys, and Booze. Now that I have a couple years under my belt, I can see how this is true even in the Orthodox Church, and it seems true everywhere else in religion for that matter. In a few cases, I can think of a fifth "B" - Bread. Some clergy eat themselves to death.
Why would people who believe in God so much do such things? Well, unlike other most people, clergy are generally judged by their affect (http://en.wiktionary.org/wiki/affect#Noun). How they behave is almost more important to their congregation than what they do. If the priest is not emotive in the right way, no matter how much he does for the community, they will always criticize him for being 'dry' or 'unfeeling' or even worse. If your priest is a 'vending machine for' your own feelings, than a priest who doesn't exude the emotions you want for yourself is utterly useless.
So, clergy often learn to exude what their people are looking for emotionally by dampening their own real emotions. They may get mad, but they cannot show it. They may be frustrated, but they will show no sign of it. Parishioners are not meeting with the priest to get God, they want something a little less powerful. They want a dose of enabling so they can go back to business as usual. So, the priest faces the daunting task of risking an empty church for the sake of honesty, or pleasing people while hiding his true self.
This leads to loneliness, and the pain of such isolation is only magnified by other clergy who look on at us, seeming to do a much better job of hiding than we do or, perhaps, actually having attained such a state where they simply don't have any negative emotions at all. They are not hiding anything, they are like 'that' all the time. This leads to further feelings of anxiety and over our inadequacies.
Now, all of those "Bs" are looking like a great escape.
Several priests I know are now suspended for 'booze' I'm sorry to say. I can understand why: the isolation, the expectations, the secrecy... it all adds up to a lot of pressure. Alcohol is cheap and effective at providing a temporary escape from the stress of life. The problem is that the stress is always there when you get back. It waits in the doorway like a faithful dog.
The problems I am describing are not limited just to clergy, even laypeople can fall under the same pressure to 'conform.' Here's an article about Mormon doping:
We are all missing the point: Jesus did not tell everyone to walk around with a smile all of the time. He told people to do what was right and repent of their own failings.
If you think your religion demands that you never ever have a negative emotion, then you are setting yourself up for addiction. The more you repress, the more you will suffer. The more you suffer, the more temptation you will have to medicate.
No, I am not advocating that we abandon ourselves to every whim: the trick is to confront and deal with negative emotions rather than hide from them. We must always be honest with ourselves. There is a time to hold back our negative emotions, but unless you are a saint don't try to fake it. Be yourself, as ugly and embarrassing as that is (especially for myself!).
Have manners, but do not be captivated by other people's expectations, as noble as they are. I warned my parish when I arrived, "You had a holy man as a priest. Now, you have me and I'm not that holy. Be careful." One person decided to test my patience the way he did my saintly predecessor, and he quickly discovered that I have none of the virtues of the man I replaced. But, I have been honest about it, and honesty seems to work for now. If it stops working, it will be time to move on. I'm not strong enough to hide all of my failings.
Religion should not be about hiding, but about being changed. If there is nothing that needs to be changed, then you don't need religion. The perfect have no need of it.