In the Corinthians’ case, their spiritual immaturity is especially reflected in their partisanship. Instead of focusing on Christ, they focus on human leaders (see also 1 Corinthians 1:12). Paul cannot help but wonder if, after all, the Corinthians might be merely human.
In other words, he questions if they really have the Spirit. What a distressing thought!
4 Quand l'un dit: Moi, je suis de Paul! et un autre: Moi, d'Apollos! n'êtes-vous pas des hommes?