Business investors look at the benefit/cost ratio. If the number looks good, they put in their money. If I receive an offer that would benefit me in some way, I look at the reward/effort ratio. Would it be worth my effort to get that reward? Now, consider if we should believe in God or not. Here the benefit or reward is infinite because you get to go to heaven! Infinity over any number is still infinity. No other ratio can possibly beat that. So, I should believe in God at any cost or effort.