Pascal's wager, haha!
I recommend also Discworld approach (Terry Pratchett has great understanding of the realities of life!). When the guy proposed this idea died, and met the gods, they each had a heavy club and had nasty thoughts of giving someone a lesson of having seemingly bright ideas...
The only thing which has bothered me for a long time is that if you choose to believe in (especially Christian) god, you have to obey some rules given by the god. But the thing which finally converted me out of any belief systems was that if you follow those rules, you are actually being selfish because then you only follow the rules since you want to get to heaven rather than accept the judgement of your true personality's actions at the end.
Also, it dawned to me that church here never did much good for those in need before modern times, it was actually the relatives. Current system is again that kind that the people already pay taxes to support the homeless, but church has pretty much nothing to do with that! Yeah, this country is really a pagan country, even though the church did its best to override the old traditions. Besides Ukko the Overlord God sounds much better than God.
Somebody already said that if you can improve things today, why do you wait and hope it will be any different in heaven? One of the best examples of this was a priest coming from Holland, (this happened in China) he saw me doing some fighting exercises in Beijing. He came to me and asked my name and if I believe in God, also asked about the reasons for the training. He also had a Chinese girl with him.
I suppose he thought I would answer that I'm from the almighty and believing Europe, I proudly believe in Christian god, and train only for the self-defence. Instead I replied honestly that I'm not in the position to argue for or against the existence of godly beings, and I train to be able to kick someone's ass (yeah, Finns have this special relation with priests). Seemingly shocked he tried to explain about the mercy of God and so there would be no need to train against threats if you believed in God.
He then continued explaining his daughter became a teenage mother, his son became crazy and is currently in asylum, and his wife cheated on him and divorced later - during the trips he has done to Asian contries preaching of the mercy of God. He said he would be happier dead, but God's mercy has kept him going. The only thought I had that where were you mister when all that happened, but this I didn't tell him. I pity for that poor Chinese girl, though. The church could choose their evangelists/priests a little bit better if you ask me. And I have my own suspicions regarding that girl also.
Oh and regarding martial arts, I have actually done only something what most of the people would consider positive with those skills. One suicide attempt (actually a devoted Christian) stopped and one foreign student saved from certain beating which resulted in short fight between me and five drunken yutes. And then there are some interventions in bar fights.
Mika