With the form of expression in this verse, comp. 1 Peter 2:1, "Putting away, therefore, all wickedness ( ἀποθέμενοι οὗν πᾶσαν κακίαν), and all guile, and hypocrisies, and envies, and all evil-speakings, as new-born babes long for the spiritual milk," etc.
Filthiness ( ῥυπαρὶαν). Here only in the New Testament, never in LXX.; but the adjective ῥυπαρός is the word used of the "filthy garments" in Zechariah 3:3, Zechariah 3:4—a narrative which illustrates the passage before us.
Kakía is not vice in general, but rather that vicious nature which is bent on doing harm to others (see Lightfoot on Colossians 3:8). Thus the two words ῥυπαρία and κακία comprise two classes of sins—the sensual and the malignant, Engrafted; rather, implanted.
The word is only found again in Wis. 12:10, where it signifies "inborn." St. James's teaching here is almost like a reminiscence of the parable of the sower (Matthew 13:3, etc). The "implanted Word" is the gospel teaching.
"The seed is the Word of God" (Luke 8:11).