The proposed reason for believing: Pascal's Wager (though most don't know the formal name). Pascal's Wager basically says that one should believe in God (in his arguement, the Christian God) because the end result of believing is always better than the end result of not believing. Basically there are four outcomes:
- One believes and there is a God - heaven
- One believes and there is no God - nothing
- One doesn't believe and there is a God - hell
- One doesn't believe and there is no God - nothing
Here are a couple of my issues with this reasoning:
1. It assumes, if there is a God and heaven, the only rewards and/or punishments are dictated by strict Christian theology. What if the following were true:
It is a common belief that only the morally good should populate heaven, and this is a reasonable belief, widely defended by theists of many varieties. Suppose there is a god who is watching us and choosing which souls of the deceased to bring to heaven, and this god really does want only the morally good to populate heaven. He will probably select from only those who made a significant and responsible effort to discover the truth. For all others are untrustworthy, being cognitively or morally inferior, or both. They will also be less likely ever to discover and commit to true beliefs about right and wrong. That is, if they have a significant and trustworthy concern for doing right and avoiding wrong, it follows necessarily that they must have a significant and trustworthy concern for knowing right and wrong. Since this knowledge requires knowledge about many fundamental facts of the universe (such as whether there is a god), it follows necessarily that such people must have a significant and trustworthy concern for always seeking out, testing, and confirming that their beliefs about such things are probably correct. Therefore, only such people can be sufficiently moral and trustworthy to deserve a place in heaven--unless god
wishes to fill heaven with the morally lazy, irresponsible, or untrustworthy. - Richard Carrier [ref]
That's just one of many, many conceived possibilities of how God could truly decide. It's entirely possible that God punishes blind or false faith.
2. How does one know that the Christian God is the one true God? If one does choose to believe in God based on Pascal's Wager, then they are rejecting other theologies that have similar outcomes for ones soul. So if one does choose the Christian God, and God turns out to be the Islamic God, they get punished anyway.
Basically what I'm getting at is that the four options presented in the wager are not the only four options, many others exist. With no proof or knowledge of what is actually true, there is no one religion (or non-religion, which is why I'm agnostic) that I can commit myself to.