Hebrews 5:11-14

11Of whom we have many things to say, and hard of interpretation, seeing ye are become dull of hearing. 12For when by reason of the time ye ought to be teachers, ye have need again that some one teach you the rudiments of the first principles of the oracles of God; and are become such as have need of milk, and not of solid food. 13For every one that partaketh of milk is without experience of the word of righteousness; for he is a babe. 14But solid food is for fullgrown men, even those who by reason of use have their senses exercised to discern good and evil.