John Colquhoun - The Believer's Duty: Obedience "From" Life Not "For" Life...

"Hence learn how the believer ought to perform the duties of holiness. He ought not to perform them for life, or in order to entitle himself to life ; but to perform them from life, from the faith and hope of eternal life. Jesus the adorable Surety fulfilled all righteousness for life to his spiritual seed: his design in doing so was to entitle them to life. Instead then of obeying for life, or thrusting your duties in the room of his surety- righteousness, your duty is to rely on his obedience for a title to life, and then to obey from life. You who have believed through grace are under the firmest obligations to advance in holiness ; but you must not, under pretense of this, rely on your performances for your title to life. This would be to erase the Surety's name out of your debt-bond, or, at least, to impute imperfection to his payment of the bond. Relying on his righteousness for all your title to the justification of life, repose the confidence of your hearts in him for grace and glory. Trust that he will be graciously and sensibly present with you at his Holy Table; saying with the Psalmist, "I shall surely be satisfied with the goodness of thy house, even of thy holy temple," Psal. lxv. 4." 

SERMON V: ON THE SURETISHIP OF CHRIST.
John Colquhoun

WLC Q. 97. What special use is there of the moral law to the regenerate?

A. Although they that are regenerate, and believe in Christ, be delivered from the moral law as a covenant of works, so as thereby they are neither justified nor condemned; yet besides the general uses thereof common to them with all men, it is of special use, to show them how much they are bound to Christ for his fulfilling it, and enduring the curse thereof in their stead, and for their good; and thereby to provoke them to more thankfulness, and to express the same in their greater care to conform themselves thereunto as the rule of their obedience.