Πᾶς ὁ γεγεννημένος ἐκ τοῦ θεοῦ ἁμαρτίαν οὐ ποιεῖ, ὅτι σπέρμα αὐτοῦ ἐν αὐτῷ μένει, καὶ οὐ δύναται ἁμαρτάνειν, ὅτι ἐκ τοῦ θεοῦ γεγέννηται (1 John 3:9-NA28).
"Everyone who has been born from God does not practice sin, for His seed remains in such one, and he cannot practice sin, for he has been born from God" (NWT-2013 Rev).
"Everyone who has been fathered by God does not practice sin, because God's seed resides in him, and thus he is not able to sin, because he has been fathered by God" (NET Bible).
Here is part of the note for 1 John 3:9 in the NET:
"The problem of the present tense of ποιεῖ (poiei) here is exactly that of the present tense of ἁμαρτάνει (Jamartanei) in 3:6. Here in 3:9 the distinction is sharply drawn between 'the one who practices sin' in 3:8, who is of the devil, and 'the one who is fathered by God' in 3:9, who 'does not practice sin.' See S. Kubo ('I John 3:9: Absolute or Habitual?' AUSS 7 : 47-56) for a fuller discussion of the author’s argument as based on a sharp antithesis between the recipients (true Christians) and the opponents (heretics)."
[END QUOTE from NET]
Moises Silva denies that 3:9 denotes habitual sin by virtue of the present "tense" itself, but Ralph Earle emphatically asserts that John intentionally employed the present tense in 3:9 to discourage the "practice" of sin. But note Richard Young and Stanley Porter's thoughts on the matter.
Young classifies 1 John 3:9 as an "iterative present" (108). He goes on to write that "the customary or habitual sense" may offer a solution to the exegetical problem in 1 John 3:6; 1 John 3:9."
Note two opposing views, however:
"Smalley (1984:158-65, 172) avoids the iterative idea by suggesting that the passages refer to the potential state of sinlessness. Turner (1965:151) goes beyond the idea of habitual acts of sin and says it refers to the condition (or state) of being a sinner." Young believes that this position confuses the imperfective and stative aspects (cf. Fanning 1990:212-217), and I would concur. There is also an informative discussion in S.M. Baugh's 1 John Reader which provides good evidence for reading 3:9 as an example of practice (ongoing action).
Baugh pens these observations: "In my opinion, the fact that John chose to use the present infinitive ἁμαρτάνειν rather than the aorist ἁμαρτάνειν, shows that he was thinking about 'sinning' in v. 9 as a characteristic action. Hence, John does not teach 'perfectionism'--that Christians can experience sinlessness in this life. Rather, when he says οὐ δύναται ἁμαρτάνειν he teaches that the genuine Christian cannot be characterized by a life of unrepentant sin" (pp. 50-51).
Baugh believes that three factors buttress this interpretation of 3:9:
(1) The immediate context.
(2) The lexical significance of ἁμαρτάνειν .
(3) The influence of δύναμαι upon the tense form of its complementary
Furthermore, Baugh thinks that since the infinitive form of ἁμαρτάνω does not appear elsewhere in the NT, John must have used the infinitive in 1 John 3:9 to signal an ongoing activity rather than a state. He concludes: "the phrase οὐ δύναται ἁμαρτάνειν in 1 John 3:9 expresses the fact that the Christian is prevented by the new birth and the abiding presence of God from falling into persistent sin" (52).