Now here we have a profound doctrine of a (let me call it) transcendent humanism, a humanism which says that Christ is the fulfillment of essential man, namely of the Adamic nature, but that this fulfillment was necessary because it didn’t occur in a straight way a break occurred, and this break in Adam, who fell away from what he essentially was supposed to become, was fulfilled in Christ. The childish innocence of Adam of course has been lost, but now the man who is tested and decided can become what he was supposed to become, namely fully human, and he can become so because we can participate in this full humanity as it has appeared in Christ. And don’t forget that this always includes eternal life. It means similitude with God with respect to participation in infinity. That’s what Christ does, and that’s what we can do too.
I always am surprised, when I go into these matters, how much better the old Christian theology was than the popular theology which developed in the 19th century how much profounder, how much more adequate to the paradox of Christianity without becoming irrationalistic or nonsential or absurd. It never did.
Of course, there were absurd elements on the borderline, on the edge, with respect to miracles, etc. But the central position was as profound as possible, namely an understanding of Christ not as an accidental event or as a transmutation of a highest being, but as fulfilled or essential humanity, and therefore always related to Adam, I. e., to man’s essential being, and to what Adam did when he broke away from himself his fallen state.
In this context, Tertullian gave the fundamental formula for the Trinity and Christology. He used a skillful juristic language which became decisive for all the future. It entered the Roman Catholic creeds which were written of course in Latin and had the power of the right word, which also has its kairos and the words of Tertullian had their “right time” in which they could “hit” and express what was going on. “Let us preserve the mystery of the Divine economy which disposes the unity into trinity, the Father, the Son and the Holy Spirit, three not in essence but in grade; not in substance but in form. ” In these words we have for the first time the word trinitas. Tertullian introduced it into the ecclesiastical language. He also speaks of the unity in the trinity, denying any form of tri-theistic tendencies.