Spiritual maturity means spiritual adulthood. The mature believer has successfully integrated and is constantly executing the plan of God for his life. The mature believer logs a maximum amount of time in fellowship — filled with the Spirit.
Spirituality: The absolute status of fellowship with God through the turning-away from a state of perpetual sin, via use of 1 John 1:9. Also termed “the filling of the Spirit.” (Antonym: Carnality). See also: “Occupation With Christ.”