Hebrews 6:1 (ISV) "Therefore, leaving behind the elementary teachings about the Messiah, let us continue to be carried along to maturity, not laying again a foundation of repentance from dead works, faith toward God,"
The Hebrew word for maturity is sachal...it's noteworthy that God defines our growth levels in His word. He also defines what is elementary and what is full age.
HEBREWS 5: 12-14 "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. For every one that useth milk is unskilful in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil."
It appears that the process of maturity or the journey from elementary to full age depends on the type of food one eats and the exercises one has accomplished.
