People can experience things which are convincing to them, but, which are not based on reality. An extract from "The False and Conflicting Experiences of Mankind: How Other Peoples' Experience Contradict Our Own Beliefs" by Vexen Crabtree (2008):
“There are many neurological and physiological causes of odd experiences in our lives. These range from ordinary tricks of the eye1 through to repeated minor epileptic fits that cause nothing more than visual (or aural) hallucinations combined with emotional cues. Many supernatural experiences can be artificially induced through neural electro-stimulation, proving their mundane basis2. Strange and unusual experiences often give rise to strange and unusual beliefs3,4 especially for those people are not inclined towards finding natural explanations for events. Experiments have found that a person's "psychological tendencies may also be used to predict exact types of 'unexplained' phenomena in which they are likely to believe" and that those who display signs of dissociation are likely to see "a given stimulus item as a paranormal creature, whether Bigfoot or an alien"5.
For example during night terrors, our brain is still suppressing bodily movement and it feels we're being forced down on to the bed, complete with much anxiety and fear. Some people have such attacks multiple times. The belief that this is a demonic attack seems natural to many and even after explaining the physiological and natural causes of night terrors, many continue to believe in a supernatural source. Of course, this is ridiculed by those who know that such attacks are really alien investigations of the Human body. Both explanations are foiled however by neuroscientists who understand that the cause of these experiences is biochemical in nature.
Cultural expectations play a large part in the interpretation of personal events, meaning that the resultant beliefs vary according to geographical region. We all find rational arguments to explain away those who experience things that contradict our own interpretation of reality - in secret, when we find people who have experienced things that we don't believe in, we all think we can explain others' experiences better than they themselves can explain them. Investigations into the physiological causes of strange beliefs comes from an ancient line of skepticism. In "The Supernatural?" by Lionel A. Weatherley (1891)6 the author intelligently outlines many such investigations - and that was well before modern neurology started making its amazing strides towards understanding the sources of experiences. Despite this knowledge, the masses remain generally unconvinced, and stick to ages-old cultural and subjective beliefs. The Christian Pentecostals have a saying, "the man with an experience is never at the mercy of the man with a doctrine"7, meaning that rationality subverts itself to experience. In total, we cannot entirely trust our experiences nor those of others, and more careful investigation is needed by all.”
Clearly the range of Human experience gives rise to many contradictions. Not all experiences can be entirely true. We know that the evident facts are sometimes not quite so factual. We have all experienced things that actually did not happen. We have dreamt, tripped, imagined and forgotten things leading us to conclusions and sternly felt beliefs in things that are not real. What range of affects can result in belief in God?
There are some physiological and neurological causes of religious and mystical experiences. These causes are purely physical, and are (now) understood scientifically - we know how they affect the brain, but in history our lack of understanding has resulted in a wide range of religious customs and beliefs9. Some are the effects of disease or dysfunction, whilst others are the result of human behaviour: (1) Diseases effecting the brain, eyes or our nervous system, (2) neurochemical imbalances, (3) fasting9, (4) exhaustion, (5) sleep and sensory deprivation10,11, (6) chanting, (7) practices of extreme austerity and (8) ritualistic behaviour and (9) ritualistic drug use12, can all induce hallucinations and other strange states of mind9.
For example, hallucinations caused by eye problems can result in surprisingly specific visions of grotesque faces with large eyes and teeth, blood running upwards, and costumed figures1 as our brain tries to interpret errant inputs13. But most hallucinations start directly in the brain and most of them are subtle and not just a matter of visual phenomenon. The same experiences can be triggered artificially by neurosurgeons, producing varied visions from mundane events such as smelling something to out of body experiences. Experimenters can consistently generate deeply meaningful religious experiences which would be utterly convincing if participants didn't know it was being generated artificially.
People interpret these episodes in terms of their local culture - Western Christians don't receive revelations of Buddhist enlightenment nor witness their previous lives, and conversely Eastern Daoists don't receive images of the Virgin Mary14. This makes it clear that mystical experiences are a result of culture and psychology, and not conduits to fundamental truths.
For more on this topic, see:
God as a fulfilment of the role of a perfect parent, of a concept of perfect abstract love, and a fulfilment of our egotistic need to feel important:
Psychologists consider experience to be projections of our expectations on to events. So that sleep apnea is experienced by UFO believers as an attempted abduction, but by those who believe in evil spirits it is experienced as an attempted possession. According to the expectations and the subconscious wishes of the person, events will be experienced in completely different ways. So, the cause of God is partially our inner wishes.
“To begin with, we know that God is a father-substitute; or, more correctly, that he is an exalted father; or, yet again, that he is a copy of a father as he is seen and experienced in childhood - by individuals in their own childhood and by mankind in its prehistory as the father of the primitive and primal horde. Later on in life the individual sees his father as something different and lesser. But the ideational image belonging to his childhood is preserved and becomes merged with the inherited memory-traces of the primal father to form the individual's idea of God.”
Sigmund Freud (1923)15
Parent figures experienced by children, those under the age of four, is quite different than how they experience them once they develop empathy. When they start realizing that their parents do not know everything, that they can hide things from their parents, and that their parents can hide things from each other, then the father becomes 'something lesser' than what he was before. Parents, before this stage, are considered omniscient and omnipotent by children. The child feels and acts as if the parent figures can do anything, solve any problem, know the child's own thoughts and know what the child is doing. After doing something that the child thinks will elicit a response from the parents, a child will expect their parents to act, punish and reward the child even if the parents were not actually present. This is the feeling of being continually and completely watched by an omniscient and ever present parent figures. This parent figure fades, in real life, when the child learns the reality of how its parents are limited, like the child itself, but the memory of this uber-parent still remains. And the want and wish for such a uber-parent to exist remains in the subconscious memory of the child as they mature.16
“Abstract thought allows us to take things to extremes. We can feel love for people who we have never seen based on their personality and communication alone. The communication medium is irrelevant. Due to our increasing capacity for empathy, we feel that others love us in return and feel we are in touch with their emotions. This is based on the feelings we have towards them, based on our own abstract thought and these are all in turn all based on our assumptions on the relationship between what is real and what is abstract.
“It is important to understand that an enormous amount of our human experience is really a response to symbols. [...] This is the peculiarity of human beings: that a symbol can gain a hold on the imagination and cause a more powerful response than the actuality that it represents.”
It is possible to create an abstract personality, based on abstract thought processes, like politics and religion, but based around a concept or idea. If we symbolize and abstract an all-knowing parent into a timeless, deathless, figure, then some find God itself.
Our need for unconditional love, our abstract philosophical minds and the way our very emotions and world view are led by our abstract representations of what we think is real can conspire to create in our minds an abstract source of love. Something we want and need since youth, and something that can frequently be lacking. The all-loving abstract god, the all-knowing and all-powerful being that we create in our minds matches all of those abstract ideas we attribute with our parents while young.
Such want and expectation, especially combined with the popular cultural memes of God-belief do lead to experiences of 'God'. That this occurs is not a valid argument against the possible existence of God, but surely places much of the belief in God on the same plane as belief in conspiracy theories and mass hysteria.”
“Our ego makes us want to feel special, wanted, watched and observed. We want to be punished when we do wrong, because we like to feel that our actions count. Psychologists and psychiatrists such as Sigmund Freud, R.D. Laing18, etc, have also held that God is a projection of the ego. God provides an imaginary fulfillment of the role required by our ego; the position of a being that ratifies our importance in the world. The less important we feel ourselves to be, the more this God can assert itself. In angst and powerlessness, people find comfort in a personal "realisation" that actually everything is ok, they are not worthless, because God cares for them. Some turn to God to fill a hole created in our heads by an impoverished ego, filling them with a sense of importance.”
God is said to be the creator of hundreds of billions of stars, planets, galaxies, and the arbiter of all the laws of nature and the creator of time itself: It is a great compliment to our pride to think that such a being cares about us personally - and not only that - but that it sometimes changes the laws of physics in order to answer prayers, or it actually even sometimes talks to us. A series of questions presented on "Pride and Ego as a Cause of Religion" by Vexen Crabtree (2006) by Brian Holtz includes:
Which indicates more pride: to believe that one's body will soon rot and decay once and for all, or to believe that one's body will be renewed for an eternal blissful afterlife in the presence of the Creator?
Which indicates more pride: to believe that no higher power cares about humanity, or to believe that the Creator of 100 billion galaxies came to Earth and suffered just for the benefit of its human inhabitants?
Which indicates more pride: to believe the universe rigidly follows natural laws, or to believe that the laws governing 100 billion galaxies are sometimes suspended because the Creator listens to one's prayers?
Which indicates more pride: to believe that no higher power cares about humanity, or to believe that gods and angels and demons are engaged in a supernatural struggle to influence one's eternal fate?
People receive all kinds of messages from God(s). One person experiences an angry God, another experience an all-loving God who cannot possibly be angry. There have been many precise and detailed accounts of what God has told people, but, these transmissions appear to contradict each other in a great number of details, and in style. This leads us to the conclusion that most of these experiences are untrue.
Once we admit that we can discount some experience of God, and simply state that some people, although they have personally experienced messages from God are actually wrong in trusting their experience, then we are faced with the atheistic possibility that actually all experiences of God are false. Einstein says that primitive and unscientific minds are drawn more heavily towards the idea of a personal God19 (1941); and this is borne out by the fact that intelligence is inversely related to religiosity. In other words, the cleverer you are, the less likely you are to believe in God. This is especially true for successful scientists. Mass opinion in Europe and most the developed world (apart from the USA) has turned against the idea that a God exists. As we learn more about the world, we realize that experiences we previously thought must have been caused by gods and spirits, are actually results of Human psychology.
Sometimes the most obvious explanations for what appear to be plain facts are actually erroneous. God is a phantasy projection of our imaginations and wants, not an existent being.
Albert Einstein20 (1930)
This parental figure that gives us pure love, that we yearn for; when we were looked after and unconditionally loved... that figure is sometimes not there in our lives, or in most people's lives, that figure quickly fades away leaving only a memory. Searching for it, we can find such a figure in philosophy. Abstract thought and ideas lead us to believe, through projection, that an all loving over-looker is there for us.
Abstract thoughts brings with it the most essential element of doubt. Where we learn not to assume we know everything and that we can always learn more. We want to learn everything, to get everything right. And we presume that this is possible. We are aiming and striving to be like an omniscient being that we can only imagine exists. However... our imagination can quietly be abstracted into things we think are real.
Combined with our need for unconditional love, even in an abstract sense, an Ultimate can form in our minds. Something we want, yearn for and desire with all our emotion. Through our amazing capacity for love and empathy, both driven by our ability to think abstractly, we are able to feel such a being is there for us.
Our very emotions and feelings, our determination and emotional well-being are based on our ability to associate emotions with abstract thought. Our emotions and feelings can become associated with abstract symbols of love that do not necessarily represent something that really exists. God can become a requirement in our hearts and minds, whether or not it exists.
This, it seems, is the most natural course of behaviour for species whose emotions are caught up with abstraction. For a species where love, controlling our emotions and minds, can be associated with symbols and ideas we are capable of putting our emotional stability on a concept, an idea.
The psychological wish for an ever-present loving parent looking over us, combined with our ability for abstract ideas to become the basis for our emotions, especially love, form the concept of God as a subconscious parent-substitute and ideal carer. The childhood memory of our seemingly all-knowing and all-capable parents, whom we continuously miss in adult life, causes some people to desire a parental god to exist.
Pride and ego incline us toward god-belief: It is more prideful to think that the creator of the billions of galaxies cares deeply about oneself, and it is a function of the ego that we want such an all-powerful eternal being to be watching and judging us. The opposite: That no-one is watching, and no-one keeps measure of our actions, is cold in comparison, so that some peoples' ego's and pride wish for there to be a god. See: Homocentricity or Anthropocentrism: Why Do Religions Think Humanity Is Central to God and Creation?.
As we can see from the different ways people experience the same event, peoples' expectations influence their reality. Examples of this include, as discussed, sleep apnea: Experienced by some as UFO abductions, and others as attempted demon possession. Of all the experiences and messages given by God, many contradict each other. From this mess of contradictory experiences, combined with the lack of any logical reason why gods would exist, I conclude that there is no God. There are human beings, our wishes, our projections and our experiences led by our own abstractions and expectations, but there is no objective, real God external to the self. See: The False and Conflicting Experiences of Mankind: How Other Peoples' Experience Contradict Our Own Beliefs.
That we can stimulate parts of the brain and induce mystical and spiritual experiences in people means that such experiences are explained by the neurological sciences whether or not there is actually a 'spiritual realm'. See: Souls do not Exist: Evidence from Science & Philosophy Against Mind-Body Dualism.
Hallucinations are easily interpreted in religious terms, and, the religious instinct towards fasting and sensory deprivation are both sought after as routes towards gaining 'divine' or 'spiritual' messages - when in reality, it is the starved brain misfiring. See: Hallucinations, Sensory Deprivation and Fasting: The Physiological Causes of Religious and Mystical Experiences: 2. Hallucinations.
The burden of proof remains firmly with the spiritualists: Experience of these types of mystical events is not proof of the reality of them, therefore different (logical or experimental) proof needs to be found. Until such proof arrives, it is not sensible to believe in god.