New Defender's Study Bible Notes
5:13 that ye may know. The most definitive basis for our assurance of salvation is true faith in “the name of the Son of God,” with whatever that entails. John has also given a number of tests for knowing that our faith in Him is true faith, not just mental assent to a tenet of faith. Such tests are noted in I John 2:3; 2:5; 2:6; 2:29; 3:2,3; 3:14; 3:18,19; 3:24; 4:13; 5:2. Compare also John 20:31.