Dear brothers and sisters, when I was with you I couldn't talk to you as I would to mature Christians. I had to talk as though you belonged to this world or as though you were infants in the Christian life.
References for 1 Corinthians 3:1
I had to feed you with milk and not with solid food, because you couldn't handle anything stronger. And you still aren't ready,
for you are still controlled by your own sinful desires. You are jealous of one another and quarrel with each other. Doesn't that prove you are controlled by your own desires? You are acting like people who don't belong to the Lord.
When one of you says, "I am a follower of Paul," and another says, "I prefer Apollos," aren't you acting like those who are not Christians?
References for 1 Corinthians 3:4