From Volume Three on the Holy Spirit - 1674 2. There is yet another part or effect of our sanctification by the Holy Ghost, which consisteth in and is called mortification of sin. As what we have already insisted on concerneth the improvement and practice of the principle of grace, wherewithal believers are endued; so what we now propose concerneth the weakening, impairing, and destroying of the contrary principle of sin, in its root and fruits, in its principle and actings.