Is there a practical difference between belief in the Big Bang Theory, which essentially came from nothing and whose origins cannot be explained, and belief in God?

First, in science, it isn't really correct to say we "believe in" theories. Theories are accepted if they are supported by *all* the evidence (observations), or rejected if they are refuted by *any* of the evidence.The Big Bang happened. All of our observations confirm it. None of our observations refute it. Why did it happen? We don't yet know, but that doesn't change the fact that it did happen.This is in contrast to the "belief" in gods. Gods, like scientific theories, are explanations for observations, true. But unlike scientific theories, there is no evidence that supports that a god is responsible for a given observation, and, because of their magical nature, there *cannot* be evidence that refutes it. Consider the following:The big bang theory assert that all distant objects in the universe are moving away from one another, and the further away they are, the faster they are moving away.Evidence that would support this: measurements of red-shift in distant galaxies (observed many, many times)Evidence that would refute this: a single distant galaxy blue-shifted toward us (never observed)The god "theory" asserts that a god made the universe.Evidence that could support this: None (note: measurements of red-shift in distant galaxies do not support this, it just means that's the way he made them)Evidence that could refute this: None (note: a single distant galaxy blue-shifted toward us would not refute this, it just means that's the way he made it)

Yes. The 'Big Bang theory' was proposed to explain the observed expansion and smoothness of the universe. Belief in the existence of the (presumably)  Christian god is based on the conviction that ancient books have a claim to knowledge about the natural world.

The Big Bang (misusing the term - it was actually a term of derision for those who didn't believe in the steady state universe) doesn't require belief - we know what happened (as well as science can "know" anything) back almost to the Planck Time the singularity became the universe. We can only theorize anything else - there can't be any evidence for it, like the CBR, but if the universe is cyclic - expands until entropy is at a maximum, collapses into a singularity, becomes a universe, expands, etc., there's no need for a god to explain the universe, so there's a difference - evidence and scientific inference vs. making something up.

One has evidence and is open to investigation the other has no evidence and is not open to investigation.

I have to say that Pausha and Serge have properly answered the question. There is not near the difference between not knowing how the Big Bang happened and not knowing why God made it happen, than the others have tried to imply. It is interesting to me that some of our esteemed scientists ascribe such outdated notions to someone who believes in God, so permit me to get off-topic to correct the false beliefs of some scientists. Not all theists believe in a mythological god of "scripture," magic, anger, etc., nor that we pray to God to get us stuff, fix things, etc. And, even though a loud minority are politically active and attempt to jam their mistaken beliefs and hypocritical notions down everyone's throats, including an almost flat earth mentality, many if not most of us are quite familiar with 30 versions of big bang and know that certainly one of them is valid. I believe the original questioner may have been trying to point out, quite validly, that even though belief and science are normally considered opposite, even the scientist has to accept that a first cause may not be knowable, similar to belief.

Faith or belief in God is a pre-requisite for the 'concept' of God to be of value in life. QM whose postulates are key to Big Bang (and which is now seriously undermining the consistency of Big Bang ) states that 'reality comes into being when the observer interacts with it' (collapse of the quantum wave function) So I think that belief in God and QM are two sides of the same fundamental concept. I did not intend to compose this as a  light-hearted response to your question.   There are more considerations around Big Bang such as entropy which also support the role of faith or the act of observing in defining reality.

Yes. One discussed an event that we can prove happened (the big bang) to create an object (the universe) that we can prove exists. The other claims that a god exists (something for which there is no evidence).

According to the Big Bang model, the Universe expanded from an extremely dense and hot state and continues to expand today. The Big Bang theory does not provide any explanation for the initial conditions of the universe; rather, it describes and explains the general evolution of the universe going forward from that point on. In short we can say that big bang is a process by which universe is growing but the cause of this process is not clear. Other major question is about the singularity ( absence of space time). For the universe to came into existence, something must exist beyond the limits of space-time. So far we have two unanswered questions 1) What does exist beyond the singularity ( boundary of space-time) ? 2) What is the cause of big bang? Here are the answers 1) God ( in the form of pure conciousness) exist beyond the boundary of space-time. 2) Resolution of God is the cause of big bang. Day by day quantum physics is coming more and more closer to the acceptance of conciousness as an important parameter of the universe that governs the different processes of the nature. Once, when conciousness be accepted as a form of energy by scientific community, then ultimately they will have to accept the existence of God.

Yes. In science 1. new MODELS are discovered through observation of phenomena - both through CONTROLLED experiments and through RANDOMISED statistical sampling 2. the phenomena is ANALYSED by RELATING to other phenomena whose MODEL is already PROVED (tested to conform to other observations) 3. the new MODEL is ADDED to the MODEL of what is already known. God is a "model" only in the sense that it FITS ALL observed phenomena, BUT. NO other "models". The biblical God makes a rainbow - the observed phenomena - to comply with a MODEL that says that God does what God wants to do. That is the MODEL of God - and there is only one. Even if there are many variations, with different names for God and different reasons for the observed phenomena. But it is self-evident that Man makes God in his own image. God does what Man wants him to do. What Man BELIEVES him to do. God is THE WORD. The model of the "Big Bang" ONLY says that the model can ONLY be DEFINED from the point in time that the "universe" CAN be defined. NOTHING is not an accurate representation of where the "universe" CAME FROM in the model. The model is not defined, and God is. There is no DIFFERENCE between the person who believes in God and the God that models where the "uinverse" CAME FROM. There is no CORRESPONDENCE between the person who does not believe in God, and the model that corresponds to the OUTSIDE of the Big Bang model. The person who does not believe in God does not believe in an "outside" if there is no observed phenomena that supports the model e.g. a universal expansion in all directions - but with NO CENTRE but does not RELATE e.g. with NO CENTRE and since this implies both MICRO and MACRO being initially EQUIVALENT once you ADD the MODEL of RELATIVITY THEORY and the MODEL of QUANTUM THEORY two CONTRADICTING MODELS at the EDGE of the OBSERVABLE EVENT (phenomena) HORIZON at the EXTREMES of the MACRO and MICRO universes explained by DIRAC showing the CORRESPONDENCE an event horizon predicted by an ASYMPTOTIC "pointing" to an ORIGIN the IMPERFECT (red shifted relative) but NON-RANDOM (quantum biased) otherwise it would be PERFECTLY WHITE distribution of WHITE in the BLACK even though the SAME model that predicts an ASYMPTOTIC ORIGIN PAST the event horizon also predicts the impossibility of it having one other than that there "has to be SOMETHING" the MODEL of which is God which for the believer in God is TRUTH and for the unbeliever is EITHER an inconvenient PARADOX or an inconvenient SINGULARITY that he would rather not HAVE to have a model for just yet.