Charles Ellicott Commentary 1 Corinthians 1:12

"Now this I mean, that each one of you saith, I am of Paul; and I of Apollos: and I of Cephas; and I of Christ." — 1 Corinthians 1:12 (ASV)

I of Christ.—It has been suggested that this is not the designation of a fourth party in the Church, but an affirmation by the Apostle, “I am of Christ,” in contrast to those referred to before, who called themselves after the names of men. But in addition to the fact that there is no change in form of expression to indicate a change of sense, we find evident traces of the existence of such a party (1 Corinthians 9:1; 2 Corinthians 10:7).