Question:
If I find my life’s fulfillment through a Christian worldview, and am no worse off in death than the unbeliever, why would I become an atheist?
Response:
Pascal's infamous wager consists of two sides: the idea that atheists are worse off if they are wrong and the idea that theists are no worse off if they are wrong. This is supposedly what justifies saying that atheism is a "bad bet," though religious theists who raise this argument tend to focus on the suffering that awaits atheists if they are wrong. Sometimes, though, they get defensive about atheist critiques by saying that they are no worse off if they are wrong, so why do atheists care?
There are a number of problems with this position. First, it treats whether one is better or worse off "in death" as the only or as the most important factor to consider. This commits the fallacy of Begging the Question because the relevancy is not explained and it tends to assume that some sort of afterlife exists, which is just as questionable as the existence of any gods. Whether one is better or worse off in life, which we all agree exists, isn't even addressed — all we hear is that one feels "fulfilled" with no indication that one really is better as a Christian.
Second, this position inappropriately compares atheism with Christianity. Atheism is simply the absence of belief in gods, it's not a philosophy, religion, ideology, world view, or anything similar. Atheism is most appropriately compared or contrasted with theism, which is just he presence of belief on at least one god and also isn't a religion, philosophy, or ideology. If someone wants to compare Christianity with something, they should compare it with some atheistic religion (like some forms of Buddhism, Ethical Culture, Religious Humanism) or some atheistic philosophy (Existentialism, Secular Humanism, Objectivism). So long as one relies on incorrect comparisons, they will inevitably arrive at unreliable conclusions.
Third, and perhaps most significantly, this position seems to argue that so long as a person feels happy and fulfilled with their beliefs or religion, then that should be enough and others shouldn't try to change their minds. I don't think anyone seriously accepts this as a general principle. There may be situations where it's valid, but overall no one will agree that simply being happy or feeling fulfilled is a reason not to argue against a set of beliefs or to promote something else.
This certainly isn't a principle which orthodox, traditional Christians (who are among those likely to ask the above question) accept. It represents an extreme sort of relativism which conservative Christians actually argue very strenuously against. Such Christians believe that there exists a real, absolute truth about the universe which we must accept and conform to regardless of whether we like it or not. Our preferences, wishes, and desires can have no impact on what is true — if something is true, we must accept this rather than simply believing whatever makes us feel good. If Christians really do value the principle that some things are true and that truth matters, then they would never argue that "feeling fulfilled" by a belief is sufficient to justify it. Atheists are arguing for what they consider true and that should be respected.
It's correct that some people do feel happy and fulfilled because of their Christian religious beliefs. That has no bearing on whether Christianity is more likely true or not, nor does it have any bearing on whether Christianity is ultimately better for you than any of the alternatives. After all, some people feel happy and fulfilled because of their Hindu, Muslim, Buddhist, and other religious beliefs as well. I don't think any Christians will accept that as a reason to regard those religions as more likely true or even merely advantageous.
Christians, at least conservative evangelical Christians, certainly won't accept that as a reason not to try to convert members of other religions to Christianity. If a Christian won't accept this argument from a non-Christian, why should non-Christians accept it from a Christian? If Christians wish to argue that their religion is valid and reasonable, they can't do so on the basis that their religion makes them happy and feel fulfilled.
Finally, the above form of this question acts as though atheism were something a person chooses, like what shirt to wear or what food to eat. It's analogous to saying "if my car gets me around and is comfortable, why would I choose to buy a different car?" Atheism is not a choice, however, any more than theism is. Atheism is a position reached when a person finds that there aren't good reasons to believe in any gods and quite a few to reject such beliefs. No one wakes up one morning and says "Hey, I think I'll be an atheist today," but they might wake up one morning and realize that they aren't a theist anymore, haven't really been for a while, and maybe should never have believed in any gods in the first place.
