In The Parable of the Ten Virgin, Thomas Shepherd asks the question of how to discern whether we are “married to the law instead of to Christ.” The understanding of this question gets to the matter of what the Puritans called “evangelical obedience.” This concept seems paradoxical: if we are saved by grace, and if we are not under the law but under grace (Rom. 6:14), then why would one such as Shepherd write, “When I speak of being married to the law instead of Christ, I do not hereby exempt yourselves from obedient to the law after you are in Christ?” (36)
He starts with the question of how do we respond when we are tempted and fall into sin. First, assume you have been troubled by sin, “what hath cheered thee?” How do you find relief for a subjective sense for the damage of sin. (36-37)
Let us say you think to yourself, “”I have forsaken them, and cast out Jonah, and there has been a calm.” If so, you are reliant upon the law for your peace of mind.
Or if you fall into sin again, how do you calm your conscience? “I have repented and been sorry for them and purposed to do no more.” But that still is not reliance upon Christ, “This is the life of the law still.”
What if the sin has been unshakeable, habitual, “you find sins prevailing againt you, and you cannot part with them”? Well, my “desire is good” and my heart has been resolved against them. “This desire is but a work of the law.”
What if you say, “I have trusted Christ.” The answer, “You have done it.”
The proposition, “As obedience to the law done by the power of Christ an evangelical work, so to perform any evangelical work from a man’s self is a legal work.” (37)
This obviously is not a comprehensive answer, but it does put us in the right direction.