1 John 3:4

ὁ ποι. τὴν ἁμ., the converse of ὁ ποι. τὴν δικ. (1 John 2:29). νόμος, the revelation of God's will, the Father's requirement of His children, an expression of the true law of their nature, ἡ ἁμ. ἐστ. ἡ ἀν.: the article in both subject and predicate make “sin” and “lawlessness” convertible and co-extensive terms.