I just want to comment on an interesting point raised early in this discussion. Sorry if this has already been said, but I'm not about to read 100+ pages.
Several people have stated that if you know the equations for an interaction, then you can know the result without carrying out the experiment. This isn't entirely true.
Assume for a moment that we understand EVERYTHING in physics, and that we are also effectively omniscient with regards to measuring the states of particles in the local space region. Now, we could for example create a perfect computerised copy of a human. We could then use a supercomputer programmed with our knowledge of physics to run a 100% accurate simulation of this human. This, effectively, would be identical to having the real person standing there, except we would take the role of God in our ability to manipulate this virtual universe. Now, all the computer is doing is running calculations, yet the end result would be a fully sentient and, by all definitions, alive human. Similarly, we could remove the computer completely and, albeit very slowly, do the maths by hand or using a calculator and create an identical simulation. This simulation would, again, be a perfect copy of the real person, and in fact would be that person. Now, no matter how abstract you make the process of running the calculations, you will always end up with a living human in the simulation. The only difference is that they are not living in the real world.
In exactly the same way, if you understand the maths accurately enough, then there is no difference between experiment and calculation. Calculations just take considerably longer.
As for whether God exists? I don't think the question is really meaningful. God is just another word for "unknown". We don't know what created the universe so people say that god did it. We didn't know about evolution until recently so people claim God was responsible. 1000 years ago we didn't know about weather patterns so we said that God was responsible for the lightning. God is simply a way for humans to claim they understand things which they do not, either to gain power or to overcome fear.
PS. How has a religion thread got to 100+ pages without being locked?