Hebrews 5:12-14

For though by this time you ought to be teachers, you have need again for someone to teach you the elementary principles of the actual words of God, and you have come to need milk and not solid food. For everyone who partakes only of milk is unacquainted with the word of righteousness, for he is an infant. But solid food is for the mature, who because of practice have their senses trained to distinguish between good and evil.