Throughout his letter, John provides strong testimony to counter those who denied that Jesus—the Son of God—truly came in the flesh. Flowing from the truth that Jesus indeed came from the Father, John draws several essential conclusions:
- We have fellowship with the Father, with Jesus His Son, and with one another—and God makes us His children.
- The blood of Jesus purifies us from all sin.
- Fellowship with God means walking in the light: choosing righteousness rather than persisting in sin, refusing to love the world or the things in it. The world will pass away, but Jesus has overcome the world.
- When we unintentionally sin and confess, God forgives and purifies us.
- We know and love God by keeping His commands and living as Jesus lived.
- Loving God necessarily means loving our brothers and sisters—“not with words or speech but with actions and in truth.”
- God promises us eternal life, and that life is found only in Jesus Christ.
Confidence in Salvation and Confidence in Prayer (vv. 13-15
John states plainly why he writes: so that Christians “may know that [they] have eternal life.” This assurance is one of the reasons 1 John is so beloved. John writes to believers not to unsettle them, but to ground them in the certainty that God loves them and that eternal life is theirs in Christ.
This confidence does not mean we have already obtained the final prize. Even Paul wrote: “Not that I have already obtained all this… but I press on.” (Philippians 3:10-14)
Rather, it means that at any given moment, a believer can rest securely in God’s love. If we continue in righteousness as John describes, heaven lies before us. As he later writes, Jesus keeps us safe, and “the evil one does not touch us” (v. 18). Paul speaks similarly: Nothing “will be able to separate us from the love of God that is in Christ Jesus our Lord” (Romans 3:38-39).
This confidence in eternal life naturally becomes confidence in prayer. When we approach God aligned with His will, we can know He hears us—and will grant our request. James echoes this in regard to wisdom: “If any of you lacks wisdom… ask God… and it will be given to you” (James 1:5).
Praying for the Sinning Believer (vv. 16-17)
John gives an example of a prayer that accords with God’s will: praying for a brother or sister who has sinned. But he distinguishes between sin that does not lead to death and sin that leads to death—a distinction much discussed over the centuries.
Possible Interpretations
1. Physical death due to sin
Paul describes believers who suffered weakness, sickness, and even death because they partook of the Lord’s Supper in an unworthy manner (1 Corinthians 11:29–32). In such cases, intercession after death is clearly impossible.
2. The sin of rejecting Christ (in context with 1 John)
John has spent much of the letter addressing false teachers who denied that Jesus came in the flesh—thus rejecting the Son and, by extension, the Father (2:23). Jesus Himself describes a similar category: “Whoever blasphemes against the Holy Spirit will never be forgiven” (Mark 3:28-29).
The false teachers’ rejection of the Spirit’s testimony fits this category.
3. Persistent, willful rebellion while claiming Christ
Some of John’s opponents taught that sin in the flesh did not matter. John refutes this repeatedly:
- “If we claim… yet walk in darkness, we lie” (1:6).
- “Whoever says, ‘I know him,’ but does not do what he commands is a liar” (2:4).
- “The one who says he is in the light but hates his brother or sister is in the darkness until now” (2:9)
- “No one who continues to sin has either seen him or known him” (3:6).
- “Anyone who does not do what is right is not God’s child, nor is anyone who does not love their brother or sister” (3:9-10).
Hebrews gives strong warnings about deliberate, ongoing rebellion (Hebrews 6:4–6; 10:26–31).
These interpretations may all fall under the broader heading of rejecting the Spirit’s testimony—whether through hard-hearted rebellion, false teaching, or attributing Christ’s work to evil.
Our Role When We See a Brother or Sister Sin
Regardless of the category of sin, prayer is essential. But prayer is not all: Scripture calls us to restore, encourage, and admonish one another. “Confess your sins to each other and pray for each other” (James 5:16). Whoever restores a wandering sinner “will save them from death” (James 5:19-20).
We pray for wisdom, for open hearts, for healing—and for God to give life.
God Protects His Children (vv. 18-20)
John gives a series of “we know” statements:
- We know that those born of God do not persist in sin.
- We know we are God’s children.
- We know the Son of God has come and given us understanding.
Because of this knowledge:
- God keeps us safe; the evil one cannot harm us.
- Although the world lies under the evil one’s control, God’s truth remains firm.
- We are “in him who is true” by being in His Son, Jesus Christ.
- Jesus is “the true God and eternal life.”
These assurances offer comfort, courage, and clarity to all believers.
“Keep Yourselves from Idols” (v. 21)
John’s ending may appear abrupt, but it summarizes the entire letter. “Dear children” echoes his earlier affection for his readers.
To “keep yourselves from idols” is to guard against anything—whether physical idol, false doctrine, or worldly influence—that would lead believers away from the true God revealed in Christ. John’s call is simple and comprehensive:
- Worship only God.
- Follow only Christ.
- Receive only what the Spirit teaches.
This is the path to eternal life.
Summary of 1 John 5:13–21
- We can be confident that we have eternal life and that God hears our prayers.
- We should pray for brothers and sisters who fall into sin.
- God protects His children and keeps them safe from the evil one.
- We must guard ourselves from idols in every form.
1 John Wrap-Up
Why is 1 John so treasured among Christians? Perhaps because it is written with deep affection and pastoral concern. John writes as one who walked with Jesus, saw Him with his own eyes, and testifies to the love of God made flesh.
He does not write to condemn but to strengthen—to give believers a foundation on which to stand when confronted with false teachings. He writes to reassure those who fear for their salvation, offering clarity, confidence, and comfort.
John calls us to active love because God first loved us. He urges obedience because obedience is how love expresses itself. He reminds us that the world has been overcome—and that victory is ours through faith. He affirms that when our desires align with God’s will, our prayers are heard.
Though the word grace never appears in the letter, the entire epistle is an exposition of God’s grace toward His children.
Thank you, John, for writing.
Thank you, Holy Spirit, for guiding his pen.
Thank you, Jesus, for revealing the Father.
And thank you, Father, for your everlasting love.