Is it rational to believe there is a God? Yes, millions of intelligent people do believe. But when most of us say "I do/don't believe in God" is that all there is? Are we just being rational? I think not.
In the popular typology found in Kiersey's book Please Understand Me II we know that there are Thinking types and Feeling types. I am the latter, as is about 50% of the general population. "Feelers" tend to make our decisons based on feelings. Some people say "I believe" which really means "I feel."
As a youth retreat leader for many years, one common problem was kids "not feeling" God. Some of them assumed that they had no faith because they did not have a great emotional rush relating to God. Well, most of life is not a great emotional rush. And feelings are tied to sleep, eating, relaxing, stress, environmental comfort and a myriad other factors. There is no reason to assume that if God exists then I will have some sort of positive feelings, even the feeling of certitude. I have long observed that sometimes a meal or a nap can be a better cure for my spiritual crisis than prayer! It helps to be aware that feelings are not a good measure of faith. And if you do not believe in God ask yourself honestly do you ever feel like you do not love your friends or family? Do you ever doubt your job is important? Do you ever feel like nothing really matters? If you are honest the answer is yes. The reason that "you don't know what you've got 'till it's gone" is because the loss produces intense feelings. It is hard to generate intense feelings 24-7-365.
In issues of faith it is helpful to assess what one's "feeling" expectation is. Do you expect to "feel" God before you believe in God? If so, how do you know what is causing the feelings you have? My feelings may dominate me at times, but I always know that my feelings are not totally trustworthy. More tomorrow.