According to some implications of string theory, 'pure' energy - in the form of unbounded strings - could possibly exist at extremely high temperatures, such as those experienced during the big bang.
The highest temperatures and pressures we are to observe are present in the Sun - which are sufficient to prevent atoms larger then helium from forming. Temperatures and prssures even greater have long been predicted to exist in certain galatic phenomena which are extreme enough to prevent the formation of even hydrogen - only subatomic particles can exist.
Yet, the attempt made by string theory to elaborate on interactions of physical entities far smaller then those - strings - has raised the possibly of a final 'level' of deformation possible - would the most extreme conditions cause matter and energy to break down all the way to strings?
Two years ago, the stage directly above string dispersion was achieved - quark-gluon plasma. Scientists at the Large Hadron Collider achieved a temperature and pressure so high it caused the matter experiencing it to break down into quarks and gluons - albeit, they were only able to maintain the conditions for a few millionths of a second. A layman's documentation of the research can be seen here:
http://www.symmetrymagazine.org/breaking/2011/05/23/lhc-experiments-dive-into-the-quark-gluon-plasma.
If it is already possible to create a quark-gluon plasma at our current technological level, the probality that string isolation could be achieved in occurances such as the Big Bang - which featured conditions millions of times more extreme then those recreated in the aforementioned experiment - is high.
But why does a string plasma matter?
According to the quantum chronodynamics branch of string theory, isolated strings would behave in odd ways - if prevented from combining with other strings to form quarks, photons, e.t.c., they would interact with each other in ways reminiscent of binary switchs, the basic logic gate in all computers and similar electronics. This means that a sufficient amount of free strings, in theory, could act like a computer.
If intelligence as measured by mental 'processing power' is required to result in sentience, then a string plasma could, by mimicking an incredibly efficient supercomputer, become self-aware. If this was to occur, the resultant being would be omnipotent - it would be formed entirely of 'pure' energy.
Such an entity would fit all monotheistic depictions of God, as one having absolute power, eternal life, e.t.c.
As for evidence for such a being, an interesting claim has already made. By combining the apparently (and inexplicitly) ordered nature of the universe with the fact that much of the mass we should observe is unaccounted for, some have cited that possible that this God does indeed exist - the massive amount of matter in the form of energy (i.e. strings) that compose its consciousness represent all the "missing" matter - that which was present at the Big Bang theory but since disappeared.
The idea is that, during the Big Bang, conditions were extreme enough to cause string isolation, and that a very large portion of the mass present essentially became sentient - God. This is an alternative to the more mainstream theory of Dark Matter - which states that the matter we should observe is indeed present, we just lack the ability to observe it for various reasons at this time.
Summary(TL;DR): According to string theory, the existence of an omnipotent being - God - is scientifically plausible. In fact, the existence of such a being would even be a valid alternative to the hypothetical Dark Matter.
Just throwing that out there, as many people dismiss the idea of God because they do not believe it is scientifly possible.