Hebrews 5:12-13 New King James Version (NKJV)
12 For though by this time you ought to be teachers, you need someone to teach you again the first principles of the [a]oracles of God; and you have come to need milk and not solid food. 13 For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe.
Hebrews 5:12-13 New International Version (NIV)
12 In fact, though by this time you ought to be teachers, you need someone to teach you the elementary truths of God’s word all over again. You need milk, not solid food! 13 Anyone who lives on milk, being still an infant, is not acquainted with the teaching about righteousness.