Pascal's Wager is used too often by believers (especially of the Christian variety) to challenge non-believers, or warn them, or something. It's been dealt with numerous times in numerous places, and is always found wanting by the very people it's supposed convince. What I have realized though, is that it's also a problem (if indeed it is a problem) for the believers.
For those unfamiliar with it, Pascal's Wager (put forth by philosopher Blaise Pascal), was formulated with the Christian God in mind. It says that when attempting to determine whether to believe in God, it can be approached as a wager, heads or tails. God exists, or he doesn't. If you believe in God and follow his teachings and commandments in life, and you're wrong, you've lost very little -- a few fleshly pleasures perhaps, but not much of consequence. If you believe in God and do as he commands, and you're right, congrats, you get heaven. So it doesn't seem such a bad thing to believe in God. However, if you do not believe in God, and you're right, you gain little over the believer. If you do not believe in God, and you're wrong -- you get hell. Therefore, you potentially gain tremendously by believing, while potentially losing horrendously if you don't believe. The only reasonable wager then is to believe.
I'm not going to bother going through all the usual problems that are put forth with this wager, because it's been done so frequently. Go ahead and Google it, you'll see. What I want to point out is the problem that I see for believers if they're wrong.
The wager says that there isn't much consequence if you're wrong, and you follow the commandments of God. Well, actually, there's a pretty big risk: the risk that you will cause or support needless suffering and immorality during your life. For example, homosexuality. If the believer follows the teachings that homosexuality is a sin, and uses that as an excuse to deny gay people a chance to love and be loved by their partners, but this is not in fact immoral, then the believer's wager has caused or supported suffering.
If you would like a more obvious example, then consider some of what is done under the auspices of the more fundamentalist Islam beliefs. If those believers are wrong, then things like honor killings, child marriages, female genital mutilation, and other abuses are all completely and utterly without a point. These horrible things will have been done to follow the commands of a non-existent God, causing suffering, misery, and potentially (even likely) caused the believer to miss out on some chances for positive, fulfilling relationships with the people s/he has harmed. I'd call that a huge risk.
Most of us don't like to be mistaken, and most of us don't like it when we make mistakes because of bad information. How much worse would it be to go against our empathetic and altruistic instincts because of a bad wager?