The unity of the Corinthian church was threatened by differences of opinion among them, which led to different parties being formed in the church. It is not clear what the different parties stood for exactly. What is clear is that the parties were associated with different church leaders.
One party followed Paul, another followed Apollos (see Acts 18:24–28), another Cephas (another name for Peter), and another, Christ! (Paul probably adds the name of Christ to this list in order to prove his point, and not because there really existed a Christ
party in the church.)
12 What I mean is that each one of you says, “I follow Paul,” or “I follow Apollos,” or “I follow Cephas,” or “I follow Christ.”