The Mayans had a phrase they said in greeting and departure... in la kesh, I am another you. This is on par with the Hindi phrase namaste... the spirit in me respects the spirit in you. Both phrases speak of our interconnectedness. No one can do anything that it does not impact on someone or something else eventually. As my college biology professor liked to stress, matter is recycled. Energy passes through.
From the perspective of a pantheist like myself, our interconnectedness is especially important in explaining how energy works. You literally are another me, and I another you, and we are both part of something much larger (as I detailed in entry #10). We have simply taken different paths to achieve the same goal, the edification and enlightenment of our higher selves towards the purpose of reintegration with the Origin. We exist simply to experience. We experience so the Origin can renew itself. Between us and the reforming Origin are gods who direct our actions towards their own ends; so that the Prime reforms according to those ideals which they feel are important.
In the grander scheme of things, demons and gods are not so very different, and in the past a demon was merely another nation's god. Disenfranchised demons (of fallen nations or made expressly by a god for darker purposes) were often recruited by gods and used in warfare, and sometimes a demon could even aspire to godhood as it evolved. So in that light, SM's designs on becoming a god are not so very unrealistic.
The material and spiritual planes do not necessarily overlap. You may have noticed a certain lack of godly influence over the last few millennia. This is because gods use up spiritual energy simply by existing on this plane. In the spiritual plane, as I've mentioned before, energy is as free as matter is here. Spirits do not have to conserve energy there; matter on the other hand...
So their "physical" interference on this plane is limited to those times when there has built up enough energy to allow them to step down from on high and muck some S--t up with an avatar. This is contingent on the two planes coming back into alignment and the harvesting of energy which has built up since the gods last visited this crazy game preserve.
Are you with me so far?
In scientific terms... all atoms and molecules are losing electrons at varying paces. They lose them; another collects them. Nothing is lost. In metaphysical terms, all things at all times on this plane are losing energy. (We are basically energy farmers, among other things.) Most of it floats away into the spiritual plane, but some of it flows into streams (ley lines) and gradually collects at nexus points and to a lesser extent in certain other places like woods and mountains, where nature spirits gather like fish in a pond. And where nexus points are located in woods and mountains, that's not a pond; that's an ocean where larger, more dangerous spiritual critters can sustain themselves.
Now, you may have noticed I said that when a creature dies, it lets off this big burst of energy. This is less than the energy it would expel over the course of its life, but it's great for a quick build up of energy for any spiritual entity looking to profit thereby on this plane. (Don't ask me about the physics of it... I'm not a physicist or mathematician.) Over the course of a creature's existence, it slowly loses energy which gradually gathers through the ley lines, creating a surplus for when the gods wake back up and start trying to get us to fall in line with their ultimate goals. When a creature's life is cut short, most of the energy is lost in a sudden burst which saturates the area like shrapnel or atomic energy from a bomb. This is why hauntings occur BTW, as an area or items become endowed with the death-burst of energy.
But, if there are any higher spiritual entities around, they can harvest that energy for their own use and build themselves up faster. When the gods began to withdraw due to the deficit of energy, humans tried to keep their patron deities on hand by sacrifice. Sometimes this did achieve some success with lesser Servitors of the gods who, requiring less energy than their masters, had not yet withdrawn and were willing to be bribed into action.
With all the wars of the last century however, some of the hungrier, less civilized spirits have woken up early (SM and some others) and decided to make a play for power. Which is not to say that the gods and their servants are not also stirring, but gods stick to rules which they drafted for themselves when they withdrew, and so until the agreed upon time for their return (fast approaching!), they will not physically interfere. SM and his fellows know this and are taking full advantage of the situation. Some of the lesser Servitors of the gods have returned and are working against them, but they are waaaay over powered. At this point, most human witches and such are more powerful than the Servitors. In fact, while the Gods are away, those who have an innate talent for manipulating this plane's energy have pretty much the only advantage against SM short of a god going after Him, which is why He tends to go after people who are sensitive to the nuances of this plane's energy.