Paul Tillich, A History Of Christian Thought
Covenants, Church Fathers.
We began the discussion of the Anti-Gnostic Fathers, Irenaeus and Tertullian, and I emphasized that the main point was the doctrine of the creator-God (put forth) against the creator-God in Gnosticism, namely, the separation of the creator from the saviour.
The history of salvation is described in three or four covenants. The first covenant is that which is given with creation, the natural law, which is ultimately the law of love and which is innate in man. Everybody has this natural law within himself.
Secondly, the law re-stated, after it has faded away when man lost his immediate innocent participation in it. The third stage, again, is law, but now law reestablished in Christ, after Judaism distorted the law of Sinai. It’s always the same law, it’s always ultimately the law of love, it’s always that which is innate in man by nature. God doesn’t give arbitrary commandments, but he restates those commandments which are identical with man’s essential nature, and which therefore are valid under all circumstances.This doctrine is very important and we must keep it in mind.
Then in Tertullian, insofar as he was a Montanist, we have a fourth covenant, the covenant with the Paraclete, the Divine Spirit, which gives the new law at the end of the days. This means the history of salvation was understood as the education of mankind in terms of a law. This was a very powerful system of thought. It made it possible to understand why the Old Testament belongs to the Christian Bible, why philosophy belongs to Christianity: they all are stages in the one history of salvation; they are not negated by the revelation in Christ, but confirmed. This should never be forgotten in Christian theology, that the problem of dualism was solved in terms of a history of salvation in different covenants. One can say that it is the Biblical idea of kairos, the “right time.” At any time the revelation must do something special.