  An alternative approach to Einstein's theory of General Relativity (GR) is
reviewed, which is motivated by a range of serious theoretical issues
inflicting the theory, such as the cosmological constant problem, presence of
non-Machian solutions, problems related with the energy-stress tensor $T^{ik}$
and unphysical solutions.
  The new approach emanates from a critical analysis of these problems,
providing a novel insight that the matter fields, together with the ensuing
gravitational field, are already present inherently in the spacetime without
taking recourse to $T^{ik}$. Supported by numerous evidences, the new insight
revolutionizes our views on the representation of the source of gravitation and
establishes the spacetime itself as the source, which becomes crucial for
understanding the unresolved issues in a unified manner. This leads to a new
paradigm in GR by establishing equation $R^{ik}=0$ as the field equation of
gravitation plus inertia in the very presence of matter.
