It has been said that habits are formed in as little as 21 days, and if a behavior is consistently repeated in that time it will become a habit. It has also been said that the best way to break a habit is to create a new one in its place. That type of thinking works in the natural realm but not in the spiritual realm. Habits are natural but holiness is spiritual. It is vital that you understand the difference.
Holiness is God given and is not the result of 21 days of consistently repeating the same behavior. For those who fully surrender themselves to God, He transforms their thinking instantaneously by imparting His nature. Holiness is God's way of saying, "Thank you, for trusting me". It overpowers every habit because habits deal with behavior while holiness deals with character. Your behavior is a reflection of your character.
Like a habit, living holy must be consistently repeated but it breeds godly character rather than a change in behavior. God replaces your character with His. Your mind becomes like God's. Your desires become like God's. Your will becomes subject to God's and your behavior reflects His character. God's methods always have an eternal purpose. So instead of living a habitual life that is subject to change in 21 days begin living a holy life which will carry you through eternity.
Let this mind be in you which was also in Christ Jesus.
So set yourselves apart to be holy, for I am the Lord your God.
Work at living in peace with everyone, and work at living a holy life, for those who are not holy will not see the Lord.