All matter and energy (such as space itself) is expanding at an accelerating rate, and has been for an unimaginable amount of time.  Infinitely longer time than what we today believe to be the beginning of existence.  "Space" extends out infinitely as well.   So the expansion of the universe will continue forever.  This idea is the basis of my theory.  I'll follow Aukum's Razaar, "All things being equal, the simplest explanation is most likely the right one.  It is more likely gravity is just caused by an everyday FORCE, rather than a magical "energy" nicknamed gravity. I'm not a physicist, nor can I spell the word, so the theory may have many small flows, and big Physics principles might be omitted.
  One day in Astronomy class, the teacher said that the difference between gravity and a force in indiscernible.  And also, scientist have been searching for gravity waves for years and years with all Sorts of high tech equipment, not to find a single trace of the existence of a "gravity" wave.  With these two facts, I propose that there is no "gravity", the illusion of gravity is just the force of the Earth expanding.  We ourselves are also expanding, so therefore we impart a little bit of "gravity" force onto the Earth.  Force can be detected though from the expanding universe, since it is not a relative measurement.
A couple examples of why I think this works are as follows: when somebody jumps into the air, for a second there is an impulse directed into the air on the human.  This subject in actuality continues to jump up with a constant velocity because there is no external force exerted on him.  The Earth though is expanding at an accelerating rate and just catches up with the subject, giving the illusion of him jumping and being "pulled back to Earth, when really the Earth is just catching up to him.  The second example: A man steps off of an airplane.  He feels no forces acting on him at all - no "gravity force".  The illusion that he is "falling to the Earth under the force of gravity is attained because the Earth is just catching up to him at an accelerating rate.  For this man to be accelerating to the Earth he would have to feel some kind of force, but he doesn't, because it doesn't exist.
A third example of why "gravity" works when the subject is found millions of miles from a planet containing "gravity".  I'll use an example where the man is equidistant between two planets of equal mass.  (Picture below) First I'll repeat, while he is out in space, no Force is felt or is present.  The reason he is not moving towards either planet is because the "space" between the two planets is also equally expanding at an accelerating rate.  Suppose the man moves 20 miles closer to Planet A.  You might ask (well, he shouldn't move because the space between the planet and him is also expanding?) not completely true.  The explanation to this includes an explanation of the inverse squared law as well.  While the space between Planet "A" and the man is expanding, as well the space between the man and planet "B" is also.  And actually the space between B and the man is growing at a faster rate because the "space" between the man and Planet B is already larger than between the man and Planet A.  So relative to the distance between man and B, the space between man and A is getting smaller, at an exponential rate rate.  Hence the inverse square law.  The further something is from a source of matter the less acceleration it experiences.  The square, because the acceleration is relative [depending on the distance between it and the source of matter.  Space is expanding it is actually expanding slower than matter is.  This is because in the situation of matter, both matter and energy are involved in the expansion.  In the vacuum of space, only the energy of space expands in turn the gap between the planet and the man becomes increasingly smaller.  The actual ration of [space energy/(matter + space energy)] expansion is relatively close to 1.  E = mc^2, mass is so minute a number compared to the energy it contains.  But when the relative distance between two masses becomes very small and they accelerate towards each other and such a high rate.  The expansion of matter will overrun the expansion of space and the two masses will collide. So at first the gap shortens slowly, but accelerates and the gap gets smaller exponentially, until the subject meets the planet, and is said to have been pulled into it.  Which leads to another theory about the Big Bang.
Well, after an unimaginable length of time the matter in the universe will expand and over run the "space energy" until all the matter and energy are touching each other in close quarters.  From the point of God, infinitely far away, the matter will look like a very small area.  Well, the matter keeps expanding at an accelerating rate, but keeps on being hindered by Running into other matter and energy, until it becomes very dense and builds up energy until the expanding matter and energy become too strong to be hindered by the constraints of surrounding matter.  You guessed it, a big explosion, and the process starts over again.  There has been an infinitely many amount of Big Bangs to "start" the universe over again.  This theory probably sounds very far out and unbelievable to modern day scientists.  So did the non-earth-centered universe theory back in the beginning of the first millennium.
 You might think I have left out something, I did.  If there is no Force of gravity, how do satellites rotate around planets?  This occurrence is relatively simple to explain, but easier to understand with pictures.  (Look below)   The satellite is initially moving parallel to the tangent of the planet.  And keeps doing so, as the satellite moves away from the center, the expanding Earth grows, and the distance perpendicularly from the centerline of the planet increases at a constant rate, because the satellite is accelerating and so is the planet, so they cancel their accelerations out.  Note: you might say the satellite can not be accelerating, but you would also say the same about the Earth's size, there was an initial force on the satellite, this is what is causing the acceleration.  At the same time though, the relative distance to the centerline parallel to the initially tangential trajectory is shortening, resulting in a vector pointed perpendicular to the tangential trajectory.  This vector continues to grow while the tangential vector decreases.  Giving the effect of the satellite changing direction.  Since its path is symmetrical, this change in direction will be constant pointed towards the planet, resulting in what appears to be a force we call gravity.