WCF 6.5.
This corruption of nature, during this life, doth remain in those that are regenerated; (1 John 1:8, 10, Rom. 7:14, 17–18, 23, James 3:2, Prov. 20:9, Eccl. 7:20) and although it be, through Christ, pardoned, and mortified; yet both itself, and all the motions thereof, are truly and properly sin. (Rom. 7:5–8, 25, Gal. 5:17)