That natural science is relevant to theology is not obvious. Many good theories have been invented to show how natural science and theology are separate. Among these theories are instrumentalism , neo-orthodoxy , and existentialism .
Existentialism identifies the inadequacy of natural science to give an account of personal selfhood.
Theology is thus concerned with the human relationship with God and natural science has nothing to say about this. Other theories stress the compatibility of natural science and theology. Among these are liberal theology and process philosophy. A theory which attempts not only to show that natural science and theology are compatible, but which incorporates the valuable insights of all the theories mentioned above is Christian existential phenomenology . This theory builds on these antecedent theories to find an overarching perspective from which a unified view of human experience can be develped.