In the Sermon on the Mount, Christ Jesus told his disciples, "Be ye therefore perfect, even as your Father which is in heaven is perfect."Matt. 5:48. It has been noted that the word "perfect" in this verse from the King James Version of the Bible can also mean "fully mature" in the original Greek.
To progress toward full maturity in a Christianly scientific sense is to come step by step to see oneself in truth as the complete spiritual likeness of God, who is Spirit, All-in-all, the great I am. And it is to come to live in a higher degree the nature of true manhood even now in one's human experience.
Growing to such maturity is the sign of a Christian's ongoing regeneration, of working out one's salvation. But this is surely something far different from the prevalent physiological and psychological view of how the human reaches maturity.