Hebrews 5:13

named by God a high priest after the order of Melchizedek.

About him we have many words to say, and hard to interpret, seeing you have become dull of hearing.

For although by this time you should be teachers, you again need to have someone teach you the rudiments of the first principles of the revelations of God. You have come to need milk, and not solid food.

But solid food is for those who are full grown, who by reason of use have their senses exercised to discern good and evil.