Dan Dennett asks a simple rhetorical question: Would you masturbate in front of your mother (or for that matter your father/grandparents/pastor/priest)?1 I bet my soul none of us has ever done so and would never ever do so. In fact we've made sure we're not seen in the act by these people (and by most others).
Now not a few Christians believe that their deity frowns upon masturbation. For instance the Catholic Church teaches that masturbation is an "intrinsically and gravely disordered action" and is an "offense against chastity."2 Christians also believe that their god, among other things, is all-seeing and is everywhere (omnipresent). So how is it that these believers are able to perform autoerotic acts in front of God? Think about it. Such believers are never alone; God is always there with them. They can lock themselves inside a hermetic bank vault and God would still be there (and everywhere else simultaneously), closer to them than all the duffel bags of cash in the room. And if they also believe in guardian angels, then surely their personal bodyguard is with them 24/7. Unless angels can become afflicted with diseases such as glaucoma, they see everything their charge does.
So I'm scratching my head here. If their deity forbids masturbation how can they ever have the gall to do it right in front of God (and angels)? Isn't that much worse, more shameful, more scandalous than wanking off in front of one's parents?
It seems to me that one possible explanation why such believers are able to commit such a proscribed act in the very presence of their deity, is that they don't fully believe--they aren't totally sold on the idea--that their deity is right there with them all the time (not least because they don't see him/it), they don't completely believe that this entity can actually see everything, or at that moment when biological urges become strong enough they go into a (transient) state of denial of their god's existence/presence. (If Ted Haggard really believed in his all-powerful, all-seeing deity, how could he have committed the acts that led to his downfall?)
But can you imagine how ludicrous and delusional such psychological trickery would be were you jacking off right in front of your parents? You could close your eyes and deny that they're there watching but that won't change the facts, would it? You would only do it if you believe that you're alone, that the walls are opaque, that there are no hidden cameras.
If you truly believe your parents are there in front you, you won't even go naked. But if you can't see, hear, feel, smell, detect by any means whatsoever your deity, and you've never seen, heard, felt, smelled this thing you worship, then maybe, just maybe, it isn't really around--and so you can touch yourself, "in private."
Given that this deity is right there in front of them all the time (and behind, above, below, to the left, right, and all around them at the same time, and see/know everything inside them including their thoughts and feelings) how is it that any believer can cheat, lie, steal, plagiarize, be hybristic, think evil thoughts, etc.? Again, one possible explanation is that they haven't bought into the belief as fully they profess. Indeed if a person believed in the reality of this all-seeing, omnipresent deity so fully that s/he has been able to make herself see and hear its presence all the time (even if only in their heads), that person cannot possibly commit any wrongdoing. How can you possibly cheat, tell a lie, steal, ... when you're always face-to-face with this omni-everything being that has the power to punish in the worst ways imaginable for eternity? So perhaps it may do believers well to become hallucinatory and see and hear their God 24/7 if they wish to become saintly. On the other hand, to be constantly aware that God is there with you every second of your life--that might just be a living hell for some. I think the denial or de facto atheism that believers practise from time to time keeps them sane and "normal."
1. Daniel Dennett, Breaking the Spell: Religion as a Natural Phenomenon, Viking, 2006, p. 227.
2. Catechism of the Catholic Church, par. 2352.