Psalm 40:8 (NASB)
Your law is within my heart
A saint doesn't need to try to be holy. His life of communion with God imparts righteousness and holiness automatically. It never occurs to a saint to step out of God's will or sin because God's law of righteousness and holiness is written on that saint's soul. A child of God will automatically shun evil and embrace God's will. It's only when he or she caves into sin, like Adam and Eve, that they begin to question what God's will is and whether something or someone is holy or not.