So, basically, you are saying that gravity is ...<quoted text>
The stress-energy tensor is essentially a description of the distribution of mass, energy, momentum, and 'stress' in a region. On the other hand, the Einstein tensor describes, essentially, the curvature of spacetime. General relativity proposes that the Einstein tensor and the stress energy tensor are equal (up to a constant proportion factor). So, essentially, mass, energy, momentum, and stress produce curvature of spacetime. Curvature means that close by paths will either converge or diverge (depending on the type of curvature). This is gravity.
I **knew** there was a use for all that High School math I took back-when...