by Marcus Loane
Simple answer: There is no evidence.
If I proposed to you that there was an invisible elephant standing on every street corner you would demand some evidence. Those who believe in God cannot provide any evidence for their fantastic claim. Personal experience does not count as that can be explained by psychology, and it is used to back up contradictory claims about Allah, Shiva etc. I could claim that I have had a personal revelation from the Elephants and my life is wonderful since I started praying to them daily. Would you be convinced that this was evidence? I hope not. You might say invisible Elephants are silly and there are not millions of people believing in them. Well there are millions of Hindus who believe in an elephant-headed god. Belief does not make something true.
There is no evidence for the hypothesis of any god. In addition there is no logical necessity for a god. Physicists sometimes propose a new particle because it is a logical necessity to fit with their theories. The new particle is often found at a later date, ie. the evidence. Physicists predicted the existence of black holes, points in space which swallow (crush to a tiny point) whole galaxies and even light. That prediction was based on existing theories which had been confirmed by other observations. Black holes is a fantastic idea so do not accuse scientists of lacking open mindedness. Years later (fairly recently) black holes were discovered. Their effects are visible through telescopes. It is now thought that there is a black hole at the centre of galaxies, including ours. When interested in the existence of something we should consider evidence or logical necessity. Everything else, like morality or what millions believe, is not relevant. The only reason I addressed those side issues is because theists keep bringing them up.
God can hardly even be described as a hypothesis (and I mean that as a criticism) because it proposes no test. When a test is proposed such as using faith to break the laws of physics or seeing if prayer can heal in double blind trials, god's proponents will always make up a reason why the test is bound to fail. A hypothesis that cannot be tested or is unlikely to ever be testable is useless. Sometimes god is even defined as untestable.
Another problem is that god is usually very poorly defined. When it is defined, it is usually given attributes that are contradictory and so cannot even logically exist. These attributes are omnipotence, omniscience, omnibenevolence and a human like intelligence and personality. More on that in my article "The gods that can and can't exist".
The god idea was often used to explain things that science had not yet explained (the gaps in our knowledge). For example thunder was god's wrath. This is called the "god of the gaps". The gaps are getting smaller all the time. The god idea is attractive to some because they do not like gaps. They do not like not knowing. However that is god as a comfort blanket. It is probable that we will never know everything. Even if we thought we did, how could we be sure? I can see the theists nodding wisely as if this somehow helps their case. It doesn't. A scientific world view accepts that we can only claim to have knowledge if we can back it up with evidence. Theists fill the gaps with guess work and then claim it is certain or Absolute Truth. We cannot have absolute truth - deal with it!
The supernatural defines itself out of existence
If the supernatural can have any effect on the universe then it would be part of the natural and detectable by science. It would no longer be supernatural. On the other hand if the supernatural has no observable effects on the universe and is not detectable in any way, how can we possibly distinguish between that and not existing at all? How can anyone claim to have any knowledge of something that has no observable effects and is not detectable in any way? How can they rationally even claim it exists?
First cause argument
One of our current gaps in knowledge is the very first instant of the
universe (and there is even progress on this). Theologians like to postulate a
god. They say "Everything must have a cause, so there must be a first
cause, and that is god". This argument is wrong. If everything must have a
cause then god must have a cause - the argument contradicts itself. The
theologians counter that god is the exception. Well if we are allowed
exceptions why not say the universe at the first instant does not need a cause?
Proposing god adds a (huge) assumption and still does not answer the supposed
problem of an uncaused cause.
First cause is less of an issue than it used to be: everything does not need a cause. Quantum mechanics provides cases of particles springing into existence uncaused. At the start of the universe quantum effects predominate and cause and effect no longer applies. Stephen Hawking's Wave Function of the Universe calculates that our particular universe emerged uncaused from the space-time foam with a probability of 95%. Now that is by no means the last word of science on the matter. Brane theory offers the tantalising prospect of explaining what happened before the "Bang" and also explaining why the laws of physics are the way we find them - the ambitiously named Theory Of Everything. If the Theory Of Everything is developed in my life time I will consider myself fantastically privileged to have been born in this era.
Some people still say, well why not call the space-time foam or pre-universe "God"? That would be wrong because of all the hidden assumptions and baggage that is associated with the word God. A physical principle or equation is not an all powerful intelligent personality who is interested in our personal lives! It would be comparable to labelling gravity with the word "God".
Why is there something instead of nothing?
Some will say, but why is there an eternal space-time foam from which the universe emerged? In other words "Why does the (pre)universe exist in the first place?" That is probably a meaningless question like "what is the temperature of gullibility?". The latter assumes that gullibility has a temperature. The former assumes the universe has a purpose. Science can unravel how the universe came to be as it is today but we cannot just assume there is a "why". Assuming a purpose, assumes an intelligence (or an evolutionary algorithm) behind it, so using the question "Why does the universe exist at all?" as part of an argument to reach the conclusion that there is an intelligence behind the universe, is a circular argument.
What is the purpose of a rock on Mars? What is the purpose of Pluto? What is the purpose of a quark? What is the purpose of a galaxy millions of light years away? What is the purpose of the Universe? The most probable answer to these questions is that there is no purpose. If you assume there is a purpose, you are assuming an intelligence (or an evolutionary algorithm) behind it, yet there is no reason to assume a purpose. We humans are often too quick to assign purpose when there is none. If we search the entire surface of the moon or Mars we will eventually find a piece that looks like a face. The face screams purpose at us yet there was no purpose, only weathering by dust storms or asteroid impacts. There are millions of potatoes in the world so some are in shapes that people have claimed depict the virgin mary or whatever their local god happens to be. Again we humans see purpose where there is none. Our brains evolved to search for purpose to make sense of interactions with others and our local environment. We are surrounded by purposeful, human designed objects. We automatically view objects and try to assign a purpose to them. Once we recognise this tendency in ourselves we can see that it no longer applies universally and should be used with caution. The universe should be assumed to have no purpose.
Some alternative views of what exists
1. Universe alone
2. Universe + God (Allah/Yahweh/Osiris.. - choose one or more from 1000's) + assorted heavens, paradises, purgatories and hells.
3. Universe + God + God's Creator and His Creator and so on
4. Universe + other universes
5. Some larger natural system containing universes
6. Universe + timeless, spaceless state from which universes may emerge naturally
7. Universe + giant ant from which it was excreted
8. Me and nothing else
I could go on, the only limit is our imagination. At the moment, all we can say to know exists (barring solipsism) is the Universe alone.