How Do I Know If I'm Mortifying Sin by the Law or by the Gospel?

In Ralph Erskine's sermon "The Strength of Sin" (see Works, 5:145ff--thanks to Tony Reinke for the reference) he has a section on the difference between gospel mortification and legal mortification. You can read the whole thing here. Below is an outline of the eight differences that Erskine identified. 1. Gospel and legal mortification differ in their principles from which they proceed. 2. They differ in their weapons with which they fight against sin. 3. They differ in the object of their mortification. 4. They differ in the reasons of the contest. 5. They differ in their motives and ends. 6. They differ in the nature of their mortification. 7. They differ in the extent of the warfare. 8. They differ in the success. HT: Matt Chandler