Also, he is the head of the Body, that is, of the church, in virtue of his primacy as the first to be born from the dead — that gives him pre-eminence over all.
Now the Promises were made to Abraham and to his offspring; it is not said, 'and to your offsprings' in the plural, but in the singular and to your offspring — which is Christ.
I am suffering now on your behalf, but I rejoice in that; I would make up the full sum of all that Christ has to suffer in my person on behalf of the church, his Body;