I am interested in how things work on EfU when it comes to those who are servants of the divine (or infernal). Specifically Clerics, Paladins and Blackguards.
Paladins seem to get most of the attention when it comes to breaking their code, but I have never really heard or seen "fallen" Clerics. (Actually, I've seen one fallen Cleric but that's because they switched deities and were in the process of earning their divine powers from their new deity.) If I am playing a cleric, as I currently am, I take the role very seriously. I don't see Cleric's as being insanely common, as in anyone who devotes themselves to a deity can become one. They have to embody the ideals of their deity (or at least strive to), uphold their deities dogma and beliefs, as well as spread the faith of their deity.
A Cleric of Ilmater might, for example, should actively be trying to alleviate the suffering of others. Different priests might have different methods, but in the end the goal is the same. A Cleric of Loviatar should actively seek to spread pain and torment, and through doing that bring people closer to her goddess.
It seems that, over all, Clerics get a huge free pass on EfU while Paladins are heavily scrutinized for every minor infraction. Certainly, it is rare that a Cleric will receive the personal attention of a deity - but every deity has scores of servitors that do just that. I've always imagined the gods watching over their priests as Santa Clause. They know when you've been naughty or nice, and if you've been naughty - if you're straying - they'll send you reminders.
These reminders might come in the form of dream visions. According to Ed Greenwood such visions are common within the Forgotten Realm's. (View what he has to say on that here, it is at the bottom of the page. It more or less sums up how I view the gods, so tell me if things are different on EfU.) I would imagine that a Cleric would receive these types of visions as a way for their deity to communicate to them what they want them to do. I would imagine that a Cleric (and even Paladins and Blackguards) would receive dream visions as a way for the divine to better align their actions with the deities goals.
In my mind, faith plays a hugely important part of the Realms even more so than faith in the real world, because the gods have been known to strike people down. Sometimes on a regular basis.
I'm not sure how the DM's view Clerics in general, but I would certainly prefer the DM's to scrutinize my Cleric(s) for spreading the word, the message and the influence of their deity, rewarding and punishing as necessary.