Hebrews 5:10

Though he were a Son, yet learned he obedience by the things which he suffered;

And being made perfect, he became the author of eternal salvation unto all them that obey him;

Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.

For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat.