WCF: Of Sanctification (XIII.1)

“…the dominion of the whole body of sin is destroyed…” (XIII. 1).

The dominion is destroyed they say, but in view of what they also say in V.5 (Of Providence) regarding the “deceitful heart” they cannot know that their “old man is crucified with Him” (Romans 6:6) for the deceitful heart which they freely acknowledge to be in possession of might be deceiving them into believing that the dominion of the body of sin had been destroyed when in reality it was alive and well.

Ironically enough, they are judged by their very own words that the body of sin is in fact NOT destroyed since it is this very body of sin that deceived them into thinking that true Christians have deceitful hearts. Their hearts are indeed deceitful (they said so themselves), but the hearts of true Christians are not deceitful.