Well I (and probably most Mormons, and IMO the Old and New Testament) would absolutely agree with you that service out of sincere love for others and a desire to do good is far more noble than serving with the thought of reward. I don't believe "all you have to say is I believe", because I think faith is not faith if you're not willing to back it up with your actions. Likewise, serving for a reward is better than no service - but it misses the point of actually becoming a happier, more loving person. I think a person who sincerely believes in God and believes we are, in any sense, his children, should feel a natural love towards others and a desire to serve Him and them. I think if a pastor feels they need to motivate with the thought of reward, they've already missed out on that very fundamental point. Going to heaven would be nice, but it shouldn't be the only reason you do good. If it gets you to start serving, great, but I don't believe anyone's going to heaven who doesn't sincerely love their fellow man.
The thing is, though, it's not like I invented my beliefs because I needed a reason to serve - I believe because of (though you may disgaree) rational reasons and experiences I've had that although I can't reproduce them or verify them to others, I consider empirical as far as myself is concerned. If I sincerely believe that to be the truth and a source of great happiness, I wouldn't call it a waste that I spent 2 years inviting others to try achieve the same. If they decline, that's fine and I think no less of them, but it's not like my beliefs are the only reason I have for trying to serve others. I still serve in other ways and for other reasons - believing in God doesn't mean I wouldn't try to do good otherwise.
>> Not all atheists lack spirituality, and not all are moral-less. You can totally believe in a greater cause without having to invent things.
Wholeheartedly agree - I hope I have not implied anything to the contrary.