Force is invisible to the human eyes. But force is powering all the motons of all the matters.

Force and matter are coexisting. There is no force, no force line, no field existing in vacuum space.

All matters are formed from atoms, therefore all forces matters carried are from the forces within atoms.

There is only one force existing in the atoms, electrostatic force. F=Ke x Q1Q2/R^2. The same charges repel each other and opposite charges attract each other.

Let's see what this force can do.

If we have a solid small positively charged ball, a solid large double-shell around it with a positively charged inner shell and a negatively charged outer shell, and some negatively charged fluid.  

Without any other force, the ball will stay still in the center of the double-shell with a distance r to the inner shell, the fluid will be attracted by the inner shell and repelled by the outer shell and float above it at a distance r1. 

We can call this system an atom, it will be a perpetual machine, a generator, and a transformer. 

If we knock it, the atom will move at the force direction, the ball will oscillate inside of the double-shell, and the fluid will oscillate outside. 

The atom now carries the kinetic energy of the whole body/mass and the thermal energy of the oscillating charged parts. Both energies are conserved.

Now if we have another atom at a distance r2, we can find two forces between the two atoms. Present science calls the positively charged building blocks of the atoms proton, the negatively charged building blocks of the atom electron.

Two hydrogen atoms 1 and 2 at any distance, proton 1 attracts electron 2 and repels proton 2, proton 2 attracts electron 1 and repels proton 1, electron 1 attracts proton 2 and repels electron 2, electron 2 attracts proton 1 and repels electron 2. The net Coulomb's force is always an attractive force which is proportional to the product of total charges within the two atoms. Total charges equal to mass. Without charges, there is no mass. This is the mechanism of universal gravitational force.

Two masses 1 and 2 at any distance, their whole body attract each other with gravity. We all know this fact from textbooks. But textbooks missed universal repulsion force.

Electrons are on the surface of atoms/matters, line of sight electrons on the two balls repel each other with Coulomb's force which is 10^39 times stronger than gravity. This super-strong electrostatic force physicists forgot is powering all phenomena in nature other than gravitation. Such as light, the so-called EM wave, photoelectric effect, photosynthesis, induction, radiation.