  It is known that, for a static fluid sphere, the GeneralRelativistic (GR)
Effective Mass Energy Density (EMD) appears to be (rho + 3 p), where rho is the
bare mass density, p is the isotropic pressure, from a purely localized view
point. But since there is no truly local definition of ``gravitational field'',
such a notion could actually be misleading. On the other hand, by using the
Tolman mass formula, we point out that, from a global perspective, the Active
Gravitational Mass Energy Density (AGMD) is sqrt{g_{00}} (rho + 3 p) and which
is obviously smaller than (rho + 3p) because g_{00} < 1. Then we show that the
AGMD eventually is (rho - 3p), i.e., exactly opposite to what is generally
believed. We further identify the AGMD to be proportional to the Ricci Scalar.
By using this fundamental and intersting property, we obtain the GR virial
theorem in terms of appropriate ``proper energies''.
