The Christian life is a life of growth. We are called to grow in holiness, or Christlikeness, if you prefer.
If we belong to Christ we are under obligation to live according to the Spirit (Rom 8:12-14). God also works in us for His good purpose (Phil 2:12-13) which means walking in the good works He has appointed for us (Eph 2:10).
The problem is that for many the idea of holiness conjures images of people praying in church or some other “sacred” activity that is divorced from everyday life. But holiness just means setting ourselves apart for God in every aspect of our lives.
Holiness means we are to extend Christ’s influence over us beyond our quiet time and church.
A relationship with Christ is more than just knowing about Christ. A saving relationship with Christ is every part of your life lived according to His will. Therefore, personal holiness, or being set apart to the Lord affects every aspect of our lives. Peter exhorted the recipients of his first letter, like the Holy One who called you, be holy yourselves also in all your behavior. If we are to be holy people, we are to be set apart for the Lord in the mundane as well as the “sacred.”
In fact, it is better to say that for someone who is holy, every part of their life is sacred because every part of their life is set apart for the Lord.