In A Systems Theory of Religion, Luhmann discusses what must be given up (and what we gain) when we give up the “old European” concept of God–the single omnipresent, omniscient, omnipotent God.
The observer God had offered a security of orientation that was nearly unequalled. If that idea of him is given up, “orientation” becomes a problem. . . . For he had homogenized existence, making it appear to be a continuum of rationality. He had guaranteed that everything that exists could be known (if not always by human beings). Not knowing was thus an anthropological (if not humanistic) idea; it was not a metaphysical one. In other words, we did not have to count on non-knowledge [Nichtwissen] being a condition for the possibility of knowledge or on efforts to know being able to result in still more ignorance. The limits on attaining knowledge were marked by the stop signs of mystery and prohibitions on curiosity.
Further, the observer God has provided a distinction (or in any case those which are most important) with a preferential side, a side on which actual existence, perfection, or nature could be found. And that had made it possible to see this side as crucial to the meaning of the distinction itself. One could consequently see man as the basis for the man/woman distinction. The city (or the political) became a basis for the polis/oikos distinction. The oral/written distinction replaced writing as a merely technical externalization. The soul (undying)/body (dying) distinction privileged eternal life. . . . The good was a basis for the good/bad distinction; the true for the true/untrue distinction. Everywhere in “old European” thought, one finds this structure of hierarchical opposition. . . .
The philosophy of deconstruction take aim at this decisive point of onto-theological metaphysics. . . .
Do we know a great deal more when we know this? What we gain certainly does not consist in a type of knowing better which–knowing being to be on one’s side–can be easily deconstructed. But what we gain is a larger structural abundance of forms available for observation, and thereby an expansion of the possibilities of communication. (130-31)
This “larger structural abundance of forms available for observation” apparently refers to forms that generate the economy, politics, law, science, education, medicine, etc., as function systems. These systems are able to observe and know something, but no single system can observe everything the way the old God had. And we cannot even combine all of the systems to know everything.
If there is no observer God that knows everything, a human being cannot tap into that observation, which means there can be no intellectual love of God (amor dei intellectualis) in Spinoza’s sense. Knowing anything always comes at the price of not knowing something else.