Expositor's Bible Commentary Commentary 1 John 5:13

"These things have I written unto you, that ye may know that ye have eternal life, [even] unto you that believe on the name of the Son of God." — 1 John 5:13 (ASV)

This verse makes the transition from the main argument to the epilogue. It reminds us of Jn 20:31, where the author said he had written his gospel so that his readers might believe in Jesus and receive eternal life in his name. This first letter of John is addressed to those who have accepted this belief but still need assurance that through this name they have indeed received eternal life. So the author refers six times in vv.15–20 (in addition to v.13) to what we believers know (GK 3857).

The false teachers present a different “knowledge” as well as a different lifestyle. The author counters with a series of tests by which the believers can evaluate the false teachers’ claims and practices. Walking in the light, obeying his commands, loving one’s brother, being steadfast in the community of faith, doing what is right—these serve as tests of whether the life that is from God has been received. When it has been received, it is only because God’s witness to his own Son as the source of that life has been accepted and believed. On this basis, we can expect God to hear us in prayer, free us from the presence and power of sin, and forgive our transgressions. Those who know these things know also that they have received eternal life.