It is my opinion that our basic beliefs, including our moral and religious views, are tied to our emotions. This is because the most primary of our beliefs begin in childhood and we are influenced by those around us as we develop. As a child, we are emotionally dependent on the adults in our life. The feelings that we have regarding right and wrong and belief in a higher being come from the negative or positive emotions that we have learned to associate with one choice or another.
Absolutely, we are imperfect beings, and as such we are incapable of being truly impartial and completely rational. Our emotions have a huge effect on the way we live our lives, including our belief system. At least to a small degree, everyone acts on their emotions, their so called gut instinct. Our beliefs are no different, we believe what we want to believe.
In religion, people start going to church at a very young age. They are taught that if they are not obedient to God, then they will go to hell. People associate with emotion. Emotion is what drives people to do stupid and illogical things. Emotion plays a key role in life and in religion.
Rationality properly understood prioritizes and reconciles emotions so that one is acting in a more consistent manner. One sacrifices certain emotional needs to meet others. For example, one desires to party hard during the weekend but knows in the long run he wants to get a degree and graduate. We might say if he doesn't party he is acting rationally and not emotionally yet his emotions towards his vision of his future is involved here. In fact the "rational" decision depends on one's values system, though I would not say people are always rational, being rational means you ponder it, you consider the costs and benefits to yourself. Though in some cases in the end you may still behave in a way that others assume is irrational because your values may be different.