1 See how immediately, from the very beginning, he casts down their pride, and dashes to the ground all their fond imagination, in that he speaks of himself as “called.” For what I have learned, says he, I discovered not myself, nor acquired by my own wisdom, but while I was persecuting and laying waste the Church I was called. Now here of Him that calls is everything: of him that is called, nothing, (so to speak,) but only to obey.
“Of Jesus Christ.” Your teacher is Christ; and do you register the names of men, as patrons of your doctrine?
“Through the will of God.” For it was God who willed that you should be saved in this way. We ourselves have wrought no good thing, but by the will of God we have attained to this salvation; and because it seemed good to him, we were called, not because we were worthy.
“And Sosthenes our brother.” Another instance of his modesty; he puts in the same rank with himself one inferior to Apollos; for great was the interval between Paul and Sosthenes. Now if where the interval was so wide he stations with himself one far beneath him, what can they have to say who despise their equals?
“Unto the Church of God.” Not “of this or of that man,” but of God.
“Which is at Corinth.” Do you see how at each word he puts down their swelling pride; training their thoughts in every way for heaven? He calls it, too, the Church “of God;” showing that it ought to be united. For if it be “of God,” it is united, and it is one, not in Corinth only, but also in all the world: for the Church's name (ἐκκλησία: properly an assembly) is not a name of separation, but of unity and concord.
“To the sanctified in Christ Jesus.” Again the name of Jesus; the names of men he finds no place for. But what is Sanctification? The Laver, the Purification. For he reminds them of their own uncleanness, from which he had freed them; and so persuades them to lowliness of mind; for not by their own good deeds, but by the loving-kindness of God, had they been sanctified.
“Called to be Saints.” For even this, to be saved by faith, is not says he, of yourselves; for you did not first draw near, but were called; so that not even this small matter is yours altogether. However, though you had drawn near, accountable as you are for innumerable wickednesses, not even so would the grace be yours, but God's. Hence also, writing to the Ephesians, he said, “By grace have you been saved through faith, and this not of yourselves;” not even the faith is yours altogether; for you were not first with your belief, but obeyed a call.
“With all who call upon the Name of our Lord Jesus Christ.” Not “of this or that man,” but “the Name of the Lord.”
Source: Homilies on First Corinthians (New Advent)