Hebrews 5:11-14

11Concerning this we have much to say, and it is hard to explain, since you have become dull and sluggish in [your spiritual] hearing and disinclined to listen.

12For though by this time you ought to be teachers [because of the time you have had to learn these truths], you actually need someone to teach you again the elementary principles of God’s word [from the beginning], and you have come to be continually in need of milk, not solid food.

13For everyone who lives on milk is [doctrinally inexperienced and] unskilled in the word of righteousness, since he is a spiritual infant.

14But solid food is for the [spiritually] mature, whose senses are trained by practice to distinguish between what is morally good and what is evil.