Ambrosiaster : Paul says this because some of the Corinthians were denigrating him. He did not preach anything different from the apostles. By calling himself a servant of Christ and a steward of the mysteries of God, Paul implicitly points out who the false apostles are. He denies that what they preach is of Christ, because it is not in accord with apostolic tradition. — COMMENTARY ON PAUL'S EPISTLES John Chrysostom : "Let a man so account of us, as of ministers of Christ, and stewards of the mysteries of God." After he had cast down their spirit, mark how again he refreshes it, saying, "as ministers of Christ." Do not thou then, letting go the Master, receive a name from the servants and ministers. "Stewards;" saith he, indicating that we ought not to give these things unto all, but unto whom it is due, and to whom it is fitting we should minister. — Homily on 1 Corinthians 10 Origen of Alexandria : There is a big difference between being a servant of Christ and a steward of the mysteries of God. Anyone who has read the Bible can be a servant of Christ, but to be a steward of the mysteries one must plumb their depths. Paul was acting as a steward of the mysteries when he commissioned Luke, for example, to write his Gospel, and when he sent Timothy to sort out the Ephesian church. I would even dare to say that in Corinth Paul acted like a servant of Christ, whereas in Ephesus he became a steward of the mysteries of God. — COMMENTARY ON 1 CORINTHIANS 2.18.10-16