.. I'm curious where you're heading, you seem to be heading towards explaining mass-energy equivalence in terms of forces. I'll hear you out, however a few points for now -

modern reference books the word energy is described by the words; "ability of matter to perform work as the result of motion or position." I disagree with the "or position part of the statement. In my opinion energy in its fundamental state IS motion of mass. The "position" of a fundamental particle of mass can not have energy if it is stationary in relation to its surroundings. If the mass is stationary and within the influence of a force then it has the potential for energy. The word force then can be associated with potential for energy

Well, this is contradicted in your next paragraph -

For instance in the macroscopic scale, I could describe an object that is suspended above the ground as having potential energy. The potential energy being due to the force of the gravitational field.

That's right - and so, the energy of the object IS determined in this case by its position (relative to some reference point). The higher an object is from the ground say, then the greater its potential energy. Similarly in electrostatics, the further a positively charged particle is from a negatively charged plate, then the greater its potential energy. In both cases, note I've specified these particles as being stationary. It's only when they are allowed to move (for instance if you let go of the ball you're holding, or if you let the rock fall of the cliff) that this potential energy becomes increasingly converted to kinetic energy of motion.

So, you were right to mention the importance of forces in defining potential energy (the gravitational force, the electrostatic force etc.), but going down a blind alley in trying to distinguish 'potential' forces from 'kinetic' forces. In physics one wants to describe things as simply and as fundamentally as possible, and forces are not as fundamental as energy, or momentum. There are problems with describing forces in physics, for example the Coriolis 'force' or the Centrifugal 'force'. These are felt (or 'observed') by someone in a rotating state, but not at all by anyone not rotating, even if they're nearby. This is a problem for physics which always wants to create a worldview which EVERYONE agrees on. This can hardly be the case when one guy observes (or feels) a force and the other guy doesn't - just because he's not moving in a certain way. For this reason, Coriolis and centrifugal forces are referred to as 'FICTITIOUS' forces.

But something is still happening there as a result of the rotating motion .. some sort of force, which may well be 'fictitious' but is still understood clearly in terms of the motion. It makes more sense then to describe things completely in terms of motion - so we end up speaking in terms of ACCELERATION rather than force. Circular motion is then described completely as constant motion in some given direction, modified by a constant acceleration in a perpendicular direction. Forces then don't come into the description at all.

More to the point, forces are 'magical' or 'occult' things which physics tries to get rid of by creating more fundamental descriptions in terms of energy, mass and momentum. For instance, Newton's gravity relies on some magical force instantaneously acting from a distance. Newton himself knew the problems with invoking this 'force' but it couldn't be factored out until General Rel described gravity not as a force, but as the easiest and most natural MOTION of a particle in curved space.

The other thing I want to mention for now is that E=mc squared comes from considerations of MOMENTUM, not of force - where momentum is mass times velocity (again, those fundamental quantities ..). In classical physics (Galilean-Newtonian relativity), momentum is the important marker for the universe looking the same to differently moving observers. For instance, the effects of a car accident have to look exactly the same to anyone regardless of their own state of motion. This is done by understanding the 'velocity' in the momentum equation, as being relative velocity, and factoring that into momentum calculations. Basically the same principle applies in Special Rel except that it is expanded to the domain of SPACETIME rather than space alone. Spacetime is a unification of time and 3D space which allows us to see the INVARIANCE, or constancy, of things with respect to each other, and not just their relative appearances. Special Rel in our everyday 3D experience gives bizarre results like space and time contracting or expanding between one observer and another. 4D spacetime however puts all this in context by showing how, on a higher plane (literally), nothing really has changed between the 2 guys, and especially that momentum has been conserved (unchanged) even though everything else looks out of whack. And for momentum to be conserved in Special Rel, mass has to be able to be varied and changeable, and especially INTERCHANGEABLE with energy of motion.

Anyway I realize this last paragraph is pretty tough, and hope to be able to make it simpler in the future. For now, these comments are a response to where I think you're heading (down the road of 'forces') which is as I said a tricky and maybe dead-end path. However please feel free to elaborate your own ideas. If I don't reply right away that would be just due to time constraints, but would hope to do so soon.

(Lucky I can touchtype 30 or so wpm ..)