Unfortunately, I Corinthians 1:12ff has been misused to produce an unnecessary guilt on the part of believers. Here's the text:
"Now I exhort you, brethren, by the name of our Lord Jesus Christ, that you all agree and that there be no divisions among you, but that you be made complete in the same mind and in the same judgment. For I have been informed concerning you, my brethren, by Chloe’s people, that there are quarrels among you. Now I mean this, that each one of you is saying, “I am of Paul,” and “I of Apollos,” and “I of Cephas,” and “I of Christ.”
The way this text has been used by some Bible teachers to create guilt is that people come away with the idea that if they have a favorite Bible teacher from whom they learn and grow, that such is sinful. But that's not what Paul is saying.
We all have a teacher or teachers from whom we learn and grow more than others. Granting that your list of teachers with whom you are familiar contains names of those who are accurate in doctrine, yet, if you have a favorite, the text is used to make you feel guilty. Again, that's not what Paul is saying.
There might be a name on your list that, although he's on the mark in doctrinal matters, to you, he's boring, repetitious to a fault, or you can't concentrate because of some mannerism he has such as having to read his sermon and never making eye contact or he says "uh," "ah" over and over.
But then there's one to whom you resonate. Maybe he comes from a background similar to yours, geographically, educationally, or vocationally. Maybe his sense of humor appeals to you. He's on the top of your list. Is that wrong? Sinful? That isn't the reason Paul is being critical of the Corinthians.
We find what he's warning against in verse 10: "that there be no divisions among you." For the Jewish believers in the Corinthian church, Peter was at the top of their list perhaps because he was the apostle to the Jews--he was the apostle who wrote I Peter specifically for Jewish converts; but the Gentiles would put Paul at the top of their list because he was the apostle to the gentiles.
The problem is that, as each group had its favorite, each group was making an issue out of it. They were quarreling. It's like we hear today from some believers: "Isn't _____________ your favorite teacher?" Then if you have someone else at the top of your list , they have nothing to do with you. But we all have our preferences and to have a preference isn't a sin, yet it's made out to be and they let it cause divisions.
We're not talking about refusing to listen to someone for legitimate reasons such as his doctrine isn't orthodox or because of his moral failures. The issue is that we aren't to cause divisions in the church by quarreling over sound teachers.