Hebrews 5:12-14

For when for the time ye ought to be teachers, ye have again need that one should teach you what are the elements of the beginning of the oracles of God, and are become such as have need of milk, and not of solid food. For every one that partakes of milk is unskilled in the word of righteousness, for he is a babe; but solid food belongs to full-grown men, who, on account of habit, have their senses exercised for distinguishing both good and evil.