1 Corinthians 3:2-3

I had to nurse you and feed you with “milk,” not with the solid food of more advanced teachings, because you weren’t ready for it. In fact, you are still not ready to be fed solid food, for you are living your lives dominated by the mind-set of the flesh. Ask yourselves: Is there jealousy among you? Do you compare yourselves with others? Do you quarrel like children and end up taking sides? If so, this proves that you are living your lives centered on yourselves, dominated by the mind-set of the flesh, and behaving like unbelievers.