The Reformed on the contrary state that all concupiscence, which certainly inclines toward evil, is sin, insofar as (1) all such concupiscence is against the law (Rom. 7:7) and thus is lawlessness, in which sin fully consists (1 John 3:4).

Moral corruption fighting against the law, for the crucifying and mortifying of which Christ himself died on the cross, if it be not properly sin, then Scripture has not explained to us what the property of any habitual sin is.

This very thing cannot be conceived, how something by way of an internal habit could be the cause of sin and not be sin. An internal cause inclining to act well is good.

Whatever differs from the norm of the law is sin: but concupiscence in the regenerate differs from the norm of the law. Therefore.

He, then, who admits not that all the desires of the flesh are sins, and that that disease of concupiscence, which they call a stimulus, is a fountain of sin, must of necessity deny that the transgression of the law is sin.