But of Him are ye in Christ Jesus, who of God is made unto us righteousness, and sanctification… – 1 Corinthians 1:30

Our sanctification is all in Christ; that is to say, it is because we are in Christ that we have the basis of sanctification, which consists in being set apart. A thing was sanctified of old, under the law, when it was set apart for God’s service. We were sanctified in Christ Jesus when we were set apart by the divine Spirit to be the Lord’s own peculiar people for ever. Election is the basis of sanctification. Moreover, the power by which we are sanctified comes to us entirely by virtue of our union with Christ. The Holy Spirit who sanctifies us through the truth, works in us by virtue of our union with Jesus. That which becomes holy in us is the new life. The old nature never changes into a holy thing; the carnal mind is not reconciled to God, neither, indeed, can be. The old man is not sent to the hospital to be healed, but to the cross to be crucified. It is not transformed and improved but doomed to die and to be buried. The ordinance of baptism…is meant to show, by our immersion in the liquid tomb, that it is by death and burial that we pass into life by the power of resurrection. If any man be in Christ, he is not an old creature mended up: he is a new creature. “Old things are passed away; behold all things are become new.” Now, it is because this new life is the great, the true matter of sanctification, and because it comes to us by virtue of our oneness with Christ, that Jesus Christ is made to us the power and the life by which we are sanctified. 

“Thou art God’s child: walk worthy of Him who is thy Father.” His love to thee will never cease. He cannot cast thee away: He is faithful and never changes, therefore love Him in return. This is a motive fit for the child of the free woman, and it moves His heart. The child of the bond woman is driven by the whip, but the child of the free woman is drawn by cords of love. “The love of Christ constraineth us;” not fear of hell but love of Christ; not fear that God will cast us away, for that He cannot do, but the joy that we are saved in the Lord with an everlasting salvation constrains us to cling to Him with all our heart and soul, for ever and ever. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/0991.cfm