1 John 3:9

Doeth no sin

(αμαρτιαν ου ποιε). Linear present active indicative as in verse 1 John 3:4 like αμαρτανε in verse 1 John 3:8. The child of God does not have the habit of sin.His seed

(σπερμα αυτου). God's seed, "the divine principle of life" (Vincent). Cf. 1 John 3:1.And he cannot sin

(κα ου δυνατα αμαρτανειν). This is a wrong translation, for this English naturally means "and he cannot commit sin" as if it were κα ου δυνατα αμαρτειν or αμαρτησα (second aorist or first aorist active infinitive). The present active infinitive αμαρτανειν can only mean "and he cannot go on sinning," as is true of αμαρτανε in verse 1 John 3:8 and αμαρτανων in verse 1 John 3:6. For the aorist subjunctive to commit a sin see αμαρτητε and αμαρτη in 1 John 2:1. A great deal of false theology has grown out of a misunderstanding of the tense of αμαρτανειν here. Paul has precisely John's idea in Romans 6:1 επιμενωμεν τη αμαρτια (shall we continue in sin, present active linear subjunctive) in contrast with αμαρτησωμεν in Romans 6:15 (shall we commit a sin, first aorist active subjunctive).