It is the renewing of our natures into the image of God. So we are enabled to obey God firstly by an inward, spiritual, ruling principle of grace, and secondly by virtue of the life and death of Jesus Christ according to the terms of the new covenant, by which God writes his laws in our hearts and enables us to obey them by the Holy Spirit indwelling us. Holiness described Holiness is a holy obedience to God arising from a renewed nature. This holy obedience is by Jesus Christ and according to the terms of the covenant of grace. This work of sanctification differs from regeneration.
Regeneration is instantaneous.
It is one single creating act, whereas sanctification is progressive. Holiness is like seed sown in the ground. It grows gradually into a full plant. The work of holiness is carried on in us by increasing and strengthening those graces of holiness which we have received and by which we obey. Whatever duties towards God men may perform, if they are not motivated by faith and love, they do not belong to that spiritual life by which we live to God.