I'm sometimes puzzled by the questions What do you believe in? or Do you believe in God? I'm not entirely certain what belief is, but I've done some thinking on the subject. As far as I can determine, I have at least three separate kinds of beliefs. I've given them these names just as a convenient way of talking about them.
Belief of the Heart basically includes those things which seem evident to me, but which are not covered by either direct experience or by rational thought. For example, neither my experience (eyes) nor my thinking (mind) give me any reason to believe in a soul. Yet I certainly feel like there's something more to my consciousness than just a bunch of neurons firing at each other. This doesn't mean that there IS something more, but it feels as if there is. That's Belief of the Heart.
Belief of the Eyes is pretty non-controversial. Within a culture, most people tend to agree on what is a bus, or a tree, etc. Those who don't are frequently put away for a long time.
The real trouble starts with Belief of the Mind, sometimes called reason and Belief of the Heart, sometimes called faith. People disagree over which of these should be given greater weight. Even within the realm of reason, people disagree over what is reasonable. I think this may be due to a another kind of belief, called intuition.
Intuition is what tells us how to form beliefs. To understand something means to be able to describe it in terms that are intuitive. For example, if I've grown up experiencing lots of physical phenomena, obeying laws of cause and effect, etc., then my intuition will be to accept the scientific method as a means of proving or disproving things. I can't understand something unless I can think of it ultimately as the result of particles obeying physical laws in the universe. If, on the other hand, I've grown up in a world of spiritual phenomena, my intuition will be formed around that, and I will have an easier time accepting spiritual explanations instead of scientific ones. This is why some people can accept (i.e., understand) an explanation that the universe was created by a supreme being, while others view that as no explanation at all.
So when people ask me what I believe, I really don't know what to tell them. My Belief of the Eyes takes a very narrow, empirical view of the universe. If I haven't seen it, it doesn't exist. My Belief of the Mind is a little more open. This belief is willing to consider all kinds of unimaginable things, simply because they follow logically from other things I believe, which in turn may follow from other beliefs, and so on. My Belief of the Heart is completely romantic and spiritual. It comprises what I want to believe, because that wanting comes from an undeniable feeling somewhere in my being.