What makes a human believe in Gods is obviously a very hard question to answer as it depends on what we humans think. However, if we go back to god beliefs of old, they did not involve any gods. They were instead supernatural entities, namely ghosts, demons and so on. Now some might say that this was the only kind of belief in a supreme being out there; others would say that this was the first and only kind of belief in a deity. Still others would claim that this is the first time that religion had ever involved a being and therefore it must have been a quite unique situation indeed.
Of course, we cannot really say anything conclusive about what makes a human believe in Gods because ultimately humans are creatures of the mind and all this has to do with our psychological makeup. This in turn leads to a rather peculiar situation where people tend to claim to be God in the name of science or other supposedly objective sources. This is something that occurs very regularly among religious believers and this is especially true when it comes to matters such as creationism and Intelligent Design. In short, religious believers tend to think that they know what a real God is supposed to have done. You can get more information about Ex Nonne Rebecca
A much more intriguing question though is what makes a human believe in abstract entities. It could be that these abstract entities are actually what makes a human believe in Gods; or it could be that the concept of God is so abstract and unknown to us that we actually cannot define it. It could also be that this concept of God is so foreign to us that we do not even have any idea what it looks like or what it might be made of.
To put things in perspective, think about this. Human beings exist in the universe and through time we have communicated with all sorts of other beings, some of them certainly as advanced as we are. We share DNA with all these other beings and we also interact regularly with them via telepathic abilities and astral travel. If it is so difficult for us to imagine any entity that could be so complex that we cannot even begin to conceive of it, then how on earth can it be denied that it exists when we know so intimately everything about other beings?
What makes a human believe in Gods is obviously the concept of a mind-body connection. The evidence of this is that many believers claim to hear sounds and images in their heads when there are no physical objects around. Many claim to have feelings of flying or to have had ghostly experiences or to have been visited by angels. Such stories are usually later revealed to be the product of an imagination caused by the surrounding effects of some sort of unusual activity. Some psychics claim to possess a direct experience of communication with a distant ancestor of theirs thousands of years ago.
So, the question of what makes a human believe in Gods is not one that can easily be answered because it involves an explanation of the mind-body connection and an explanation of the effects of imagination upon the experience of memory and imagination upon the perception of events outside the physical world. Only a person who has made himself very comfortable in the company of certain very special beings, like ghosts or aliens, would understand what I mean here. I am therefore very reluctant to even ask this question since, to me, it already shows an inadequate level of understanding of how consciousness and intelligence operate and how they interact. If you want my advice just remember that you might need psychic help to get a grip on these questions if you really want to understand the nature of your beliefs.