Hebrews 5:11-14 - Advanced Teaching Hindered By Immaturity
11 Concerning Whom we have much to say and difficult to explain, since ye have become dull of hearing. 12 For even when, on account of the time, ye ought to be teachers, ye again have need that some one teach you the first elements of the oracles of God, and have become such as have need of milk, and not of solid food; 13 for every one who partakes of milk is inexperienced in the word of righteousness, for he is a babe; 14 but solid food is for full-grown men, who by practice have their senses trained for the discernment both of good and evil.