Man and Sin by Piet Schoonenberg (1964) 1.7AQ

[The True God should encompass all three categories of existence: thirdness, secondness and firstness.

Why?

All three categories are Real. So is God.

Relations cannot be seen, heard, touched, smelled or tasted. Neither can God. To me, the word “God” touches base with relationality.

The word “true” goes with actuality. It would be a contradiction, a “not true”, if God did not encompass the actuality of relations in addition to the actuality of actuality itself in addition to the actuality of the realm of possibility.

The word “one” goes with possibility. God is possible. God makes all things possible. God makes our relations with Himself possible. Even though these statements seem to contradict, they are included in the realm of possibilities. God encompasses all that was, is, and will be.]