When we recall the other metaphors in Scripture where good fruit is a sign of true spiritual life and fruitlessness is a sign of false believers (for example, Matt. 3:8–10; 7:15–20; 12:33–35), we already have an indication that the author is speaking of people whose most trustworthy evidence of their spiritual condition (the fruit they bear) is negative, suggesting that the author is talking about people who are not genuinely Christians.
