difference between theistic and non-theistic system: spiritual realm transcending man

From this point of view, the logical consequence of monotheistic thought is the negation of all “theology,” of all “knowledge about God.” Yet, there remains a difference between such a radical non-theological view and a non-theistic system, as we find it, for instance, in early Buddhism or in Taoism.
In all theistic systems, even a non-theological, mystical one, there is the assumption of the reality of the spiritual realm, as one transcending man, giving meaning and validity to man's spiritual powers and his striving for salvation and inner birth. In a non-theistic system, there exists no spiritual realm outside of man or transcending him. The realm of love, reason and justice exists as a reality only because, and inasmuch as, man has been able to develop these powers in himself throughout the process of his evolution. In this view there is no meaning to life, except the meaning man himself gives to it; man is utterly alone except inasmuch as he helps another.