Hebrews 5:12

For though by this time you ought to be teachers, you need someone to teach you again the first principles of the oracles of God; and you have come to need milk and not solid food.

Surrounding context

5:11 of whom we have much to say, and hard to explain, since you have become dull of hearing.

5:12 For though by this time you ought to be teachers, you need someone to teach you again the first principles of the oracles of God; and you have come to need milk and not solid food.

5:13 For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe.

Translation and sources