Is not believing the existence of God rational?

In economics, we assume that every individuals are rational. Rational individuals will make choices which maximize their objective functions, subject to constraints.

In finance theory, we partly believe that every individuals are also behaving rationally and they will minimize risk, for any given level of return. Minimizing risk is rational.

Now, how is it related to believing the existence of God? Why is 'not believing the existence of God' probably not a rational thing to do?

Let see the following arguments,
1. If God does not exist, then there is no difference between believing His existence and not believing His existence. Everyone (believers and non-believers) will be doing fine in the end.

2. If God exists and He has rules or commands for you to follow, then it makes difference on whether you are believing on His existence.
If you are not believing on His existence and therefore certainly you are not going to listen to Him, then it is likely that your might break His rules and it is likely that you might reap something you do not like in the end, such as punishments.
If you are believing on His existence and you are listening to Him, then your life or life-after-death is likely to go well and you will be blessed by all the good things from Him, due to your obedience to Him.
Furthermore, His rules or commands are teaching you good. His rules do not teach you to do something harmful to your life. Right? So, it is a double benefit.

The conclusions are :
A. If you do not believe on His existence, you will be fine only in condition 1
B. If you believe on His existence, you will be fine in both, condition 1 and 2.

On (A), your 'investment risk' is only half-hedged. But on (B), your 'investment risk' is fully hedged. If you are rational, then you will choose to take full-hedge, instead on half-hedged your 'investment'.

Life is also a kind of 'investment'. Make sure you manage the 'risk' well, so that you could reap the benefit on the maturity date.

If I were you, I will choose to believe on His existence, and listen to Him. I am a rational person. Are you rational?

Disclaimer : It is just a thought, which might be worthwhile to consider.