Which side has the most to lose?

1. There's a perennial dispute between Christians and atheists, where each side thinks the other side has fundamentally mistaken priorities. Both sides think the other side suffers from an irredeemable lost opportunity. Atheists think Christians fritter away the only life they're going to get in their vain hope for a pipe dream that will never materialize. Given that there is no heaven, hell, resurrection, or world to come, the only rational course of action is to make the most of our one unrepeatable opportunity rather than wasting time lamenting our mortality. 

Conversely, Christians think atheists fritter away the opportunity to gain eternal bliss by clinging to this fleeting life. They think atheists suffer from a massive lack of perspective. Who's right?

2. On the one hand, it's hard to see what Christians have to lose even if they're mistaken. I say that for the sake of argument, not because I think there's a realistic possibility that they are mistaken. I'm just addressing the atheist viewpoint on their own terms. 

i) What exactly, are Christians missing out on? The cliche example is promiscuous sex. But bracketing morality, what's so great about promiscuous sex? Is promiscuous sex more fulfilling than monogamous sex? Was Hugh Hefner's life characterized by contentment and joy? Or was it more like drinking salt water, where you're more thirsty after you had a sip than before, and every time you have a sip, you're increasingly thirsty? The very fact that highly promiscuous men are so promiscuous is evidence that their sexual lifestyle is chronically unsatisfying.  

ii) Moreover, most guys never have the opportunities of a Hugh Hefner or Warren Beatty. Even if you'd like to sleep with every beautiful woman you see, that doesn't mean every beautiful woman would like to sleep with you. You must be able to bring something extra special to the table to have that kind of entree. The buy-in for a seat at that table is way above the pay grade of most lumpen. 

iii) In addition, isn't there something ridiculous about rampant promiscuity? If you could cover her face, could you tell the difference? Does the sex feel different from one babe to the next? Aren't they essentially interchangeable? 

iv) Furthermore, male sexual prowess declines with age. Erogenous zones become less sensitive. So that at a strictly sensual level, sex offers less and less. 

v) Finally, do atheists generally lead happier lives than Christians? Not that I can see. So it doesn't seem like a big sacrifice to be a Christian on that score.

vi) Admittedly, there are duties that atheists can shirk if. They can abandon an ailing family member if that crimps their style. But that means the appeal of atheism is nihilistic. 

3. On the other hand, having convinced themselves that this life is all you get, I think most atheists are impatient or irate at Christians who fixate on the meaning of life questions. What's the point of harping on how bad it is if that's the undeniable reality? There's nothing you can do about that.

But by cushioning themselves from the full implications of their position, by pushing that into the back of their minds, by refusing to allow the implications to become unbearable, they deny themselves the incentive to consider the possibility that atheism is false and Christianity is true. Because they don't push their own position to the limit, there's no overriding motivation to change course. They can muddle along because they never really take it to heart. They pull back to spare their feelings. The issue loses urgency because they sedated the pinched nerve of nihilism.