But just as He who called you is holy, so be holy in all you do;
for it is written: 'Be holy for I am holy.'
(1 Peter 1:15-16)
God calls all Christians to be holy. Why? Because He is holy. He calls us not to be like other Christians (to 'copy' their holiness), rather, He calls us to be like Himself.
Holiness is an essential aspect of God's nature, it describes both the majesty of God and the purity and moral perfection of His nature. In understanding the nature of God's holiness we need to understand that God hates sin. As the prophet Habakkuk declared: Your eyes are too pure to look on evil; you cannot tolerate wrong (Habakkuk 1:13).
Sometimes we try to justify some action that our conscience calls us to question. We often defend ourselves by saying, "Well, that's just the way I am," or even, "Well, I'm still growing in that area of my life." However, God does not accept these excuses. He hates sin with a perfect hatred. All wrongs, no matter what their size or description, are sin, and God hates sin.
In understanding God's absolute hatred for sin, it makes me all the more thankful for what Christ has done for me. His perfect holiness has become mine; my sins are gone and I am as clean from all sin before God.
It's this thankfulness that should drive us all to holiness. We need to make every effort...to be holy; without holiness no one will see the Lord (Hebrews 12:14). We need to hate sin like God hates it - I gain understanding from Your precepts; therefore I hate every wrong path (Psalm 119:104). God's standard of holiness is perfect; and this is what He holds us to. Thanks to Christ we can begin to attain this holiness already in this life.
I can do all things through Christ who strengthens me.
(Philippians 4:13)