We are told that we should worship God because if we do not, we risk burning in Hell. This is something called Pascal's Wager; that we should bet on God existing, because the potential consequences of not believing are so large.
This fails in a number of ways.
First, is a god worthy of our worship? One that holds you hostage, who is so egotistical, that if you do not acknowledge his existence he will torture you forever? Wasn't our country founded on the idea that tyranny is a poor way to lead a nation? Wouldn't the cosmic tyranny of such a deity be even worse? In some religions, the mere thought that God does not exist is a crime from which there is no redemption. Even in mainstream Christianity, dieing as a non-believer warrants your entry to eternal pain and suffering. The most egotistical madman on Earth would never condemn you to such a fate; even those who suffered in Nazi concentration camps, at Darfur, or in Somalia were eventually released to death. Their suffering was finite.
When you say that such a god is just, you are saying that people like me deserve a fate worse than the worst suffering our world has ever known. Now, you might say that you are not condemning me there -- your god is. Very well, but then I ask whether you think that your god is either more or less just than you are. Obviously, if such a being is less just than you are, then I would rather worship you than it. But if you say that your god is more just than yourself, then condemning me to such a harsh fate should be something that you should strive for. If it's not something you strive for -- if you would condemn the person who would threaten me with such harm -- then you must condemn your god.
But wait! -- you say. It's not your god which threatens me with such harm; rather, I am condemning myself to such a place!
Well, let's think about that. Was it not God who set up the rules in the first place? Was it not God who is said to be all powerful and all knowing? In what sense, precisely, would one say that this being isn't responsible? What is it that He is not responsible for?
Indeed, if such a being existed, he would be responsible for all that is and could ever be.
But there are still at least 3 other ways in which Pascal's wager fails.
Let's suppose that such a god was worthy of my worship, for whatever reason. Which god would that be?
The Christians say that it is their god, while the Muslims say that it is theirs. The Jehovah's Witnesses think that God will cast everyone else -- even other Christians -- into Hell. In fact, name a religion in which non-belief is punishable by eternal suffering, and you can find someone who says that it is their deity we must oblige ourselves to worship. But note how this whole thing is constructed; it's construed as a bet to be taken without regard for evidence and only with regard to potential consequences. Therefore, in making a choice, we must list every such belief system and weigh their potential consequences off between each other.
What you find when you do this is that all such belief systems promise the same infinite rewards for belief and infinite punishments for non-belief. Worship the wrong deity, and that deity will surely cast you into Hell. At least that much is true of both Christianity and Islam.
This is some kind of stand still; we find ourselves unable to choose religions on this basis.
But it gets worse.
Since we are simply weighing possibilities off against each other, we should weigh all possibilities. Even ones that don't reflect religions that you find in the world. After all, what basis do we have to decide that options we come up with right now are illegitimate?
Let's consider another God-concept, call it Fred. Now Fred created life in this universe to test our incredulity. If you believe in things for which there is no evidence -- such as Fred or other gods -- he will cast you into Hell. Surely it would be a mistake to worship Fred, but it would also be a mistake to worship any other gods. Because if you did worship other gods, then Fred could potentially punish you. Vis a vis Fred, you should worship no gods.
What this tells us is that the entire construction is illegitimate. We should not choose beliefs on the basis of their potential consequences alone; we need to break the tie by considering the various kinds of evidence and arguments either for or against all of these things.
Yet I find it worth mentioning that there is another way in which Pascal's Wager fails.
Suppose that all of the arguments I offered already didn't work, and that I really would be better off if I believed that your god existed.
Even then, how should I start believing? Belief is not entirely voluntary, if it ever even is. Certainly, the available evidence is either insufficient or directly undermines belief in a god. So convincing myself on the basis of evidence is out.
I couldn't simply profess belief either. You can't trick God, especially if he knows everything. And even if I could trick God, why should I trick the being who you claim is supposed to be the object of our love?
Maybe I could go around, doing various kinds of activities to compel myself to believe. But even if I could do that, wouldn't God see this as a deception and cast me into the flames nonetheless? I certainly wouldn't be coming to God wholeheartedly; I would be casting a bet for fear of perpetual torment.
But, again, I ask you whether a loving god would ever even put us in the position of making that sort of a decision. Is that the deity to whose allegiance you profess, or do you make a mockery of your own beliefs by using such a callous argument?