CatBus, the problem with your imaginary duck hypothetical is that it relates to nothing. If theists viewed God in that way it would be just as nonsensical.
The duck was a man-made invention that was purpose-built to be an entity that can neither be disproven nor fully understood. So in that sense it’s exactly like gods – the fact that theists and atheists view such things differently was the point. The feathers were added to highlight the implausibility angle.
Most theists believe in God based on what they can perceive and find it implausible that a deity doesn’t exist based on those perceptions. There are very flawed conceptions of God and I agree with Frink, at least to an extent, that really understanding God is beyond our capacity. But that doesn’t mean we can’t have a basic (and necessarily flawed) understanding that does us some good.
And here I agree. I think religion does more good than harm, which is where I part ways with jerkwads* like Richard Dawkins. Religion helps people in tangible ways regardless of the underlying truth of the tenets (and perhaps if the duck hypothesis were more fully fleshed out, I could find a way to make belief in the duck provide similar tangible benefits). So in that sense it doesn’t matter if God exists or not, believing in him is probably a net positive if you can swing it. I just can’t swing it, that’s all.
* I know we’re supposed to be polite in the Religion thread, so I suppose I shouldn’t say “jerkwads”. What I meant was “assholes”.